How much science can you do on a tablet?

Apple have announced both their iPad Air and Mini Retina this month, and we fully expect Google to follow with a refresh to the Nexus 10. Due to excellent battery life, portability, and mature application stores, I've tried working on both iOS and Android tablets (the Asus Transformer Infinity, the Nexus 10, and briefly, the iPad 3) for my work in scientific research, with mixed results. Unfortunately, I've not had a go with the Microsoft Surface range, but there are some excellent blog posts by Mark O'Connor to assist me in my review (albeit from a programmer's, rather than a scientist's, point of view).

It's a recurring question (of mine, of the internet's) whether a tablet can indeed replace a desktop and/or laptop for some, most, or even all your scientific research needs. This may be with or without a keyboard attachment (this blurs the lines between laptops, 'hybrids' with dockable touchscreens, and tablets). Of course, my answer to this will be general, and heavily biased by my experiences and needs. Everyone has a different workflow and specific discipline, each requiring unique and personalised technological demands. But this is why comment boxes were invented: do chip in below (or on Google Plus) with your opinions.

Requirements

Let's remove the low-hanging obstructions first. If you have access to a supercomputer for heavy lifting, like running hefty computer scripts, then tablets are viable; however, not if you need to carry round your CPU heft. Let's also assume that, if you need professional-grade image editing or other proprietary software, you won't even consider the lightweight alternatives. (Journalist reviews of Chromebooks and tablets as productivity replacements are often negativity skewed due to their disproportionate reliance on software such as Photoshop.)

I need to following in my entire workflow:

• Access to Mendeley for scientific article reading, management, annotation, and bibliography creation
• Access to a GUI word processors (e.g. Google Docs, MS Word) and LaTeX typesetting (preferably cloud-based like sharelatex.com). 
• Access via SSH to the university supercomputer (remote access to edit and run scripts for my research)

The following qualities are encouraged in my device of choice:

• Screen size big enough to see a lot of code, images, writing; but small enough to be portable
• VGA or HDMI out for presentations
• Long battery life for working remotely, at conferences, etc
• Openness and access to free software

General issues

Both Android and iOS tablets run on ARM processors. This is an architecture: the computer is set up differently to your typical PC (which often run x86 processors). Apps or programs written for one architecture cannot simply work on the other one without being recompiled. In addition, (non-Pro) Surface tablets run a ARM-specific OS called Windows 8 RT. ARM architecture typically gives devices excellent battery life (not always...) but less computational heft. If you're doing mostly less-CPU-intensive tasks, such as coding, writing, and reading, modern mid- and high-end tablets have the power. The other issue is that the apps you require have to be (1) written for your mobile OS of choice, and (2) has to be optimised for your tablet. This is not usually an issue on iOS and Android, but Windows RT currently falls short in the quality of ecosystem, as reported by many other sites. On an optimistic note, Android once upon a time had a much lower quality of tablet apps in comparison to iPads, but has now arguably caught up.

If you do a lot of writing, a bluetooth or dockable keyboard is essential. This begs the question: don't they already have screens that attach to keyboards? The advantage of a removable keyboard and ARM-powered heart is the flexibility to slouch-and-read versus sit-and-type - and the freedom from being tethered to a power source.

Let's look at OS- and ecosystem-specific issues.

iOS

The only tablets that run iOS are the iPads. As mentioned, I've only had 1-2 weeks of iPad experience. Apps can be more polished than those seen on Android and Surface tablets, but in my experience, you had to pay a lot more, and a lot more often, for suitable apps. I found Android to have a lot of excellent Google apps (free) and open-source software/ports (free), but the applications were sometimes buggy or ugly (if this matters to you). The blogosphere has contrasting arguments about ecosystem app prices, however, and statistics alone do not tell the story. Some developers charge for features after you've downloaded their free app; others require you to update to a new (paid) version for continued development.

iPads are more locked-down; this might result in a more secure system, and may protect battery life against badly-written power-sucking apps, but it can make it hard when trying to browse files, administrate at a system levels, etc. This ultimately was the knock-out blow for my budding iOS adoption: for example, I need to be able to easily upload/download files when working remotely.

Android

Simply, you've got more choice here. Android tablets are made by Samsung, Asus, Google, and many other companies. You won't find a dockable iPad; you won't find an iPad with a dedicated and specialised stylus. However, build quality tends to fall short of the iPad's industrial-yet-pleasing design. 

Windows (RT)

There's the Surface 2, which runs Windows RT, in line with the rest of this list. But there's the Surface Pro 2, too, which has x86 architecture. The Surface Pro is best described as a touch-screen laptop with a removable keyboard, rather than a tablet, and is almost double the price of the entry-level iPad/Nexus 10. It can run Windows 8 programs, rather than simpler apps, but battery life is inferior. It's ultimately the comparison of apples and oranges. As such, I will only consider the Surface 2 (ARM) here.

As mentioned, Windows RT is still developing; more worryingly, it's not clear if it will be allowed to continue to develop. Companies have, one by one, stopped making ARM-powered Microsoft devices, and instead concentrated on x86 devices instead. The excellent keyboard options that the Surface has available may be a moot point if the OS languishes in its current state, behind Android and iOS.

On the other hand, if you require MS Word above all else, you can't beat the Surface 2. MS Office comes free of charge with the device, and it is almost identical to the typical PC (x86) version.

My experience

I found tablets to comfortably perform a lot of common tasks in my work. I found that writing was good in word processing apps (Apple's Pages, Android's Google Drive/Docs), though a little more difficult on sharelatex.com (using a web browser on a tablet is not still on par with laptops, but e.g. the Google Chrome team are on the path to merging the two branches). This was similar across devices I used. Reading was also excellent on all three of the iPad, Asus Transformer Infinity, and Nexus 10. Ten inches is the minimum for PDF reading/annotating if you don't want to be constantly zooming and scrolling, and a high-resolution screen is also important when studying images and text. Using SSH apps, I could log on to my university supercomputer and edit/run code. I could even write code locally and upload it later, when offline. I could manage my Mendeley library almost completely via apps and the browser, thanks to a wonderful application.

However, the screen size was prohibitive at times; multitasking was a pain; web-browsing could be laggy; and OS updates on Android often broke as many features as they fixed (a common issue with Google, who seem to value cutting-edge over stability). Some have said that a 10-inch screen forces you to concentrate on the task at hand, bottlenecking/sharpening (delete as appropriate) your focus and attention. Others, me included, are so scatter-brained with code and writing/reading that a large surface area is required; tabs and windows litter two or more monitors; alt-tab or its equivalent just won't cut it. Most importantly, apps might be a good approximation, but if they can't beat a full-blown program on a (x86) laptop, you're left wondering if it's possible to skimp. In my case, the most important program was Chrome, as I (can) do most my work in the browser. Google Presentations isn't ready for tablets yet, either, and that is my go-to application for PowerPoint-style presentations (on my Chromebook).

The worst experience was with Asus. My Infinity tablet, while beautiful, broke often. It's more truthful to say my five Asus tablets. In the end, I took the refund rather than waiting for Asus to fix yet another mechanical issue. Also, Asus tablets have a common processing bottleneck where the computer chip can't seem to do two things at once, like downloading an app update and type at the same time. I also faced nothing but problems when connecting to an overhead projector to show a PDF. You just can't risk these issues cropping up on the day of a scientific presentation! On the contrary, I didn't see the same fragility with the Nexus 10 and iPad.

Summary

Today, I use a Chromebook Pixel (x86 laptop) for my day-in, day-out workflow, and this speaks volumes. Ultimately, one needs reliability. I didn't find this physically with Asus tablets, and I didn't entirely find it software-wise in the app stores on both iOS and Android (though we're almost there). One also needs productivity; if this requires a large screen, then it's going to have to come from a laptop as it stands. But if you like the modular focus of full-screen apps, it won't be a problem for you. And if you want to type quickly and efficiently, you need a hardware keyboard, begging the question: "And so what's left to make me choose a tablet over a laptop?" And here's where I hold the candle of optimism for tablet (and portable/cloud) computing as a whole: battery life should be all-day, apps and OSs should be lightweight and easy to maintain, and there should be plentiful development for applications. Here, tablets (and Chromebooks) are side-by-side, if not well past, the level of standard laptops that run Windows and Mac OS. So I'd answer my title question as such: close to all but not close enough. You can't replace the laptop or desktop completely as it stands. Let's see if the new Nexus 10 and attendant update to Android (4.4) appear enough to make me change my mind.

Let me know if you have any other solutions or workflows. I probably have a lot more to say on this topic, but this was a rough overview of the major issues and experiences I've had.