The multiple user support is especially handy for tablets like the new Nexus 10, which are much more likely to be shared, and now offer quick and easy user switching right from the lockscreen.
It was impossible to find a position that allowed this reviewer to stretch across the screen with his thumb while keeping the lock key within easy reach.
Even with that island-style arrangement, there aren't many undersized buttons here -- the Enter, Shift, Backspace and Caps Lock keys are all full-sized, and easy to hit without looking away from the screen.