I got Wipeout cause it reminded me of good ole F-Zero back in the SNES days (which haven't really ended due to the wonders of emulation
).
I'm about halfway through the campaign and the difficulty only really cranks up at that point in the higher speed classes. For me that's when it's get difficult to not blow up from crashing too much.
I find that the Dpad gives better control than the joystick cause of how I hold the PSP I guess.