This is the Kensington Keyfolio case/keyboard. It is one of several new combo cases/keyboards for iPad. It's lightweight and fully protected by a rubber membrane. And yet it is very sensitive. In fact, almost too sensitive, I seem to hit keys inadvertently quite often so far.
I have very large hands, but still, amazingly, I seem to be able to work with smaller keyboards, even touch-typing, I'm not sure how. I've used a ThinkOutside foldable successfully.
The Keyfolio is missing a right-side shift key, which bothers me, as does the placement of the apostrophe key at the bottom instead of right. I'm not sure I could get used to using those without looking down each time.
It is of course quite smaller than a full sized keyboard, since its designed to fit into the footprint of the iPad which is shorter than a full keyboard. The Keyfolio is even more than an inch shorter than the compact Apple Wireless Keyboard (without numeric pad).
But right off the bat I work faster with it than with the iPad's screen keyboard by a mile, and I can certainly use it when I have reason.
I am doing a comparison to the keyboard on the MacBook Air, 11-inch. It is a very nice one although I tend to prefer a longer key travel (how far you press a key down), and so far at the very least a lot faster than the Keyfolio keyboard/case. That maybe should not surprise me, but it is also nearly two hundred grams *lighter* than the combination of the former with my iPad. And so what is the advantage of the iPad? Certainly none hardware wise, since the macbook's screen and keyboard are both better. (This tells you about the sharpness of the Air screen, since the iPad screen is really good. Next to the Air screen it looks fuzzy.)
They are both very quiet to type on.
So the question becomes: do you need your iPad with related software? Or do you need your MacBook with related software? The MacBook has a huge legacy of Mac OS X software to draw on, many thing which can't be done on an iPad, or at least in quite limited or clumsier ways. Usually.
Of course the MacBook Air is at least $400 more expensive than the iPad with the Folio keyboard, depending on configuration. But the weight advantage of the iPad is doubtful when you need a keyboard too.
I am not sure I can think of any software for the iPad, unless it's a game or such thing, which you can't get similarly for the Macbook.
In fact the 11-inch MacBook Air is just an amazing machine. The quality and feel for it is so superior to anything I know, the keyboard is full sized, it feels speedy for any normal use, and yet it is very thin and only weighs one kilo, less than two pounds.
A few years ago I visited my family and I used my 12-inch PowerBook which they used to make. And my sister said to somebody over the phone: "you should see this beautiful computer Eolake is using!" And while I thought that one was the bee's knee's (I still have it), it's not a patch on the MacBook Air. I dare any geek to hold it and not fall in love.