I own both phones. Ive had my 920 for ages as my primary phone and I got the 1320 to use as a mp3 player (with a 64gb microsd card).
HOWEVER, after using it for a few days, i wacked my sim card in there just to try it out and havent taken it out since!
The screen size is big which is pretty awesome imho, battery life absolutely destroys the 920, which was the biggest problem i have with my 920. The 920 lasts max 11h or so with light usage. The 1320 with pretty heavy usage can last me two days easy (and i mean 48h when i say that).
Only downside is the camera. It's not bad, but it isnt great. Dont really miss Wireless charging as i dont need to charge it very often anymore. So great only charging your phone every 3 days. Great feeling.
Performance wise they're pretty much the same, so they feel identical.
So basically it boils down to, if you want a great camera and dont like phablets, get the 920. Otherwise, the 1320 is for you! Plus at only $280 unlocked its a steal! (Or less in some countries)
Edit: Just realised this post is old as hell.