So, without further ado, let me take you through a number of use cases...
1. Watching Video
This is one of the most often cited things a tablet computer is supposed to be good at.
But is it, really?
If you want to watch video at home you are most likely much better off doing on a TV screen, no? I mean, it's much bigger, it's in front of a comfy sofa, you don't need to cradle it in your own arms... Need I say more?
Even if you want to watch a film in the loo your large screen mobile phone is probably better suited to the task - witnessed also by the fact that an alarmingly large percentage of them are already covered in poo.
I will give you that, if you are rich enough to travel First Class (which you may be, if you already own a tablet computer, and especially if it is an iPad), it may make sense on public transport. Excluding the Tube, of course, where you'd probably soon not have to worry about the space you need as your prized tablet will be stolen at the next stop.
So, no, sorry: not really something to give you your money's worth.
2. Listening to Music
Included here for completeness. Even the original Sony Walkman was decidedly tiny compared to any tablet computer you care to name (or own). On top of that, tablet computers do not make a good Ghetto Blasters either. Not for very long, in any case.
Ah! You may say. What's wrong with doing your e-mail on a tablet computer? Surely it's good enough for that.
Well, if you said reading your e-mail I might have agreed (but see below). However, unless you are the only person in the world who has people writing to them, but does not need to reply with more that yes or no - ever, then I'm afraid you're out of luck. Just try composing any reasonably long and/or complex e-mail response on a keyboardless tablet. No? I didn't think so. And if the correspondence requires both reading and editing documents (text, spreadsheet, presentation) then you're doubly out of luck (again, see below).
Oh, I'm sure you can augment your tablet experience by adding a keyboard, maybe even a mouse, and a stand. But then is that a tablet any more? Sounds to me more like a decomposed laptop, but with the added pain of not really being able to compose it anywhere you like. I bet even long haul flights would whizz by if you had to assemble your tablet-cum-workstation, then tear it down again. Even in First Class.
If I were cruel, I'd say: see above. But I'm not. Going to say it. However, writing anything but a (very) short text message is a pain on a touch screen. You know it. I know it. And yet we may be trying (I know I am now and again, but only on the phone). Useless.
Erm, no. Not really. Yes, the glossies may look way better on a colour LCD than on 16-shades-of-grey eInk screen. And most current e-readers do not handle PDF files very well. But you still read quite long books? Is it very easy to hold half a kilo of a tablet for as long as it takes to read a Terry Pratchett novel? Yes, I know it's over before you know it, in a blink of an eye, and you hold your breath the whole time. But then, if that were really true, you'd be very blue in the face (if not dead), your eyes would have dried out and look like prunes, and having finished before knowing it you'd probably miss all the fun, too!
So, just be sensible and get yourself a Kindle (plus, porn is better on a laptop, trust me - leaves both hands free).
And that, dear reader, is pretty much all I have to say on the topic of tablets right now. While I'm sure I could just as easily come up with at least another five use cases for which a tablet computer is a poor fit, but I'll leave that exercise for you.
However, I'd be very much amiss if I didn't also tell you what I think would be a tablet saviour. And, believe it or not, I think it is Siri. Well, OK. Not Siri as such. Something along those lines, but way more advanced. And I mean SF advanced. Advanced to the point where I could have spoken this whole post into my tablet computer, in my broken non-native speaker accent, telling it where and how to format it, and so on, and so forth... You catch my drift. If not, go watch Star Trek, or something.
Which is not to say I won't be getting a tablet computer before I am defrosted in 2525. It just means that I certainly won't be paying through the nose, and by various limbs, for the privilege of having a slab weighing too much and capable of too little. I may even tell you which one it is once I get it. Just don't hold your breath. Unless you're being frozen for posterity at the same time, that is...
I am aware of Asus's valiant efforts with the Slider and Transformer. Still, all other non-keyboard gripes apply...