i thought it was just my imagination! I was landing jumping puzzles and platforming jumps in general on psp hardware just fine but I felt like I couldn't land my timings as well on my vitas
it's so strange though because apparently it's not emulation (which is usually the culprit for input lag) it's actually native psp hardware inside the vita if I recall correctly
I think it's a mix of native hardware and "some" emulation to get psp games working on vita, hence why a lot of psp games actually perform better on vita than they did on original psp (even if the psp was in 333mhz mode)