When I was evaluating my options for tablets I would go to HMV in Islington at lunchtime and spend a little time playing with each of the Android tabs and the iPad.
One thing that I immediately found strikingly obvious was that often the keyboards did not seem to pick up my key presses when typing quickly. I called the shop assistant over and asked if they really were this bad. He laughed and told me if i picked up the tablet and put it on something else, it'd work fine - I did this, putting it down on a cardboard box and low and behold, it picked up every key press with no delay. This happened on ALL of the tablets.
It turns out this is a problem with capacitive touch screens and interference. In HMV they put all of their tech on this large metal bench, alongside countless other bits and bobs like speakers and laptops. When the tablet is laid flat on the desk, the interference screws up the touchscreen.
Incidentally, i ended up buying an iPad and can touch-type like nobodies business on it with no problems at all.