Whispersync is a good feature if you only buy amazon books but it doesn't work on books that you don't buy from amazon. Since I rarely buy books that feature is useless to me.
As far as touchscreens - for turning pages I still use buttons but for me main pluses of touchscreen are for navigational use as well as dictionary look up. On Kindle if you want to look up a word that is not on top of the page you have to navigate to it using the four way controller which takes time and lots of clicks. By the time you get to the word you don't want to look it up. On Sony all you do is just double tap lightly on the word and voila
