Camera - infinately better (exaggeration, but still applicable)
Battery - overall, and consistantly better (though my Inspire battery is nearly 11 months older than Titan)
Screen - black levels seem to be better
Download speeds - Microcell, seems the same browsing the web.
Voice quality - Have heard no complaints so far, though I have not tested scientifically myself. There are several threads of complaints in this reguard.
IMO, since I had the Inspire and Focus S, 4.3" is my perfect size for typing - I make nearly no mistakes at near iPhone 3GS/4S (only metric I have for "good") speeds - though for youtube clips and movies (long flights), 4.7" is neat to have :)