The first thing fat vita owners will notice is the fact vita slim is more lighter and thinner less 20% of the weight and 15mm thick and the curvy design is way more confortable and friendly to your hands palm and that makes vita more portable device and the screen is actually a bit bigger than the old model.The finish of the rear has been changed from glossy to soft matt plastic wich there will no more have a slippery feel the finger grips on the rear touchpad are more bigger where there will be no longer more accidentaly press the light up button on HOME as been changed for a pair of leds on the top one for battery life and another for notifications/bluetooth wich will dont distract you on your gameplay and don't affect your screen the mistery port was also changed by a larger gamecard slot and the same slot as been moved to the centre top of the console the charger port is no more a proprietary cable as been replaced by a micro usb port wich every recent smartphone has , the PS Vita buttons have been redisigned the HOME , START and SELECT buttons are now round and have a clicky response wich is better to press and the other buttons are now more clicky responsive like the d-pad too , the speaker grilles also have redesigned from a rectange to a rounded one with more holles , also the volume is more louder , surrounded and better it's crisp and clear the analogs sticks are no much difference they are just a bit more thigh for no slip the front camera is quite the same just have a bigger ring for a better design , the rear camera is the same , considering they are not a smartphone , the cameras are good the shoulder buttons R ,L are also improved they are  more firm have a better feel and no more feel losse. The screen was one of the changes , from a OLED to a LCD , wich now the colours feels better and more natural than the oversatured OLED screen. Now a portable device the battery is a big influence , vita slim passed from 3-4 hours of the old vita to 6-7 hours of constant gaming with max brightness and sound to vita slim. Vita slim as now 1gb of internal storage for emergencys and extra storage vita slim also fully charges more quickly than the old vita. That's it all the vita ergonomics are better and with that rounded design improved buttons , lighter and thinner the device fits perfectly on the palm of your hands and you can feel a bigger pleasure when holding it , the screen fits perfectly with all thouse natural colours , the battery life was a big improvement too and the 1gb storage was also a good idea , everything on the vita slim was a big upgrade now we can have a 100% portable device. to see other user reviews in photos , click on the link. PS Vita Slim - users reviews