I’ve had loads of fun from my PSP. Great screen, great sound, easy to use. The only ‘cons’ I found is the UMD, as you say, playing off a stick would be much easier for travel. Homebrew firmware available that might do it. Stock battery life OK but the original PSP has a long life battery option.
LocoRoco is addictive and the music will drive you potty, in a good way. When you start trying to sing it, you know it’s time for a break.
Wipeout Pure is the best ‘driving’ game I’ve played on it, absolutely awesome conversion.
I might sell mine with games and accessories. Drop me a mail if you are interested in photos and details!