Picked up some new stuff today. I went to pick up my Circle Pad Pro and while I was there I spotted a copy of Dawn of Sorrow, only this was a "Konami's Best" release and I've never seen it before, so I snatched that up. Also, I found P3 Portable and decided to give this version a shot, since I've heard 2 camps saying which is better, this or FES. Now I just have to find my charging cable for the PSP... since it's battery is bone dry (naturally).
I've got FES (for the PS2) and the P3Portable version that you just got as well.
So far, I've only played the PS2 one (which I loved).
IIRC, the differences are that, in the PSP version, you can also play as a female protagonist (obviously changing/adding social-links) and you have control over your entire party instead of just controlling the main w/ the rest controlled by AI).
Also, I think that "The Answer" is missing on the PSP version (no great loss, imo).
I *think* that the rest of the changes are just the obvious differences in cut-scenes, voice-acting, etc.