I'm thinking of selling my 32GB iPhone 4 and 'upgrading' to a 4S. I'm too far invested (read: stubborn!) to upgrade to a 5 and have to replace all of my attachments, camera lenses, cases, dock connector-style accessories etc, but the 4 is just becoming annoying slow/sluggish as the iOS gets more and more advanced. Just wondering whether anyone here has upgraded from a 4 to a 4S and what your experiences/opinions were. Is it a noticeable difference, in terms of speed/responsiveness etc? Or would I be better off just sucking it up and getting a 5??