The screen for me between the 2 and the 3 was significant enough for me to get used to using the side-press next page button rather than the front press button. I would guess it would be the same for the K2 to the KT.
Kindle CS is really awesome, why not just buy one and see? If you don't like it, call CS and they'll send you a label to send it back in the original box and refund pretty quick
