Call me old-fashioned. Maybe it's just that both my smartphone and my tablet really suck (in terms of having a small display and a really slow CPU), but I don't really see myself trying to do actual work on a tablet/smartphone. Office applications are pretty keyboard-heavy, and with the on-screen keyboard, there is not enough space left to do anything serious (again: at least on my devices, your experience might be totally different!).
(I heard there are desktop systems running Android, complete with mouse and keyboard - that would be a very different story, of course!)
I use a tablet with a small Bluetooth keyboard. It's still much more portable than almost any netbook (I can carry the pair in the pockets of my winter jacket), while being good enough for short term tasks like SSHing into some server or writing a few emails.
Sounds like this is just a viewer.
That being said, I'd never do a lot of work on a smartphone/tablet, but if I was reviewing something and needed to correct a spelling error or make a quick change, it'd be nice to have that capability on my smartphone.
in terms of having a small display and a really slow CPU
One of those $100 Intel-powered Android tablets with the Z3745 processors has a processor that, core for core, equals a Pentium III or better. But instead of one core, it has four of them. And dramatically higher memory bandwidth. And SIMD. And a GPU. And shockingly fast flash storage.
And it's probably running at least a 1280x720 screen, though some options obviously go dramatically higher.
In ~2000, when these sorts of specs were common, we did all of our office work, software development, etc, on much less power.
Yeah, my tablet has a single core ARM CPU, and a 1024x600 display. Subtract the space taken up by the on-screen keyboard, and working is not much fun any more.
Also, I like having a physical keyboard. With a tablet, I end up using one hand to hold the tablet and one hand for typing. :-|
Like I said, on different devices the situation might be quite different, but my tablet is no good for working.
I can confirm that these quad-core Bay-Trail Atom processors are surprisingly fast and since it's an x86-64 CPU it is available with Windows 8.1 too and can handle Microsoft Office without a problem. The ASUS Transformer Book T100 even comes with an Office license and has detachable keyboard.
(I heard there are desktop systems running Android, complete with mouse and keyboard - that would be a very different story, of course!)