While I don't have an original iPad to compare it with I will admit it can kind of dig into you hand, but I think that I heavily dependent on how you are holding it, and for how long.
Right now I am holding it in landscape mode, with my left hand holding it from the bottom while I type, that seems very comfortable. My thumb is under the space bar and my first three finger are cradling from behind.
The only time I have any discomfort is when I am holding it in landscape mode from the side.