Without substitutes, the sales of psv are often ruined by psp. Mainly psp is still playing games, but psv's game lineup is slightly weak. And psv is not compatible with umd of psp. And cracking the game of playing psp can't be done now, (there was a loophole to brush) psv hasn't been cracked yet.
Functionally, the touch screen, back touch, camera, gyroscope and double rocker are improved. The biggest difference is that the function is improved a lot, and the screen resolution is four times that of psp.