Played for about 2 hours last night before my repeated glances at FF12 laying nearby finally got the best of me and I fired it up instead.
The loading times are long, as usual with PSP games, but really I could see this as only a problem if you did one mission right after another. Just crusing around the island there is no loading, of course. I've only done 2 missions but already I can tell the usual top notch voicework typical of Rockstar games is in full effect.
Targetting is still terrible, but we knew that already. I found a Mayhem mission and failed it because tapping the R shoulder button to target the gang members I was supposed to be wiping out seemed to never target the guy nearest to me who was filling me full of holes. Just something to get used to all over again.
Upon dying in the Mayhem mission I was pleased to see a floating padlock icon outside the hospital. Seems they've introduced a means of getting whatever weapons you had in your possession back after getting killed (well, knocked out and dragged to the hospital). At the time I had a few grenades and a pistol and the lock icon told me it would be $2k to get my weapons back, which of course I didn't have, having just started the game. Still, a welcome addition for later in the game I'm sure.
The highlight for me, as with past GTA games, was the radio. I listened to the talk station and in no time was giggling uncontrollably. After playing Saint's Row for 25+ hours, coming back to Rockstar's radio stations was like a breath of fresh air. No one does it better.