Shortly after buying a mibox of course I tried psp emulation performance, saw that it was sub par, and basically never touched it again.

I have just recently found out that it can emulate less than 60 fps games just fine.

Here is a list of 20,30 fps games for psp. (There might be more)

PPSSPP Forums

List includes; Metal gear solid, Ace combat, Tony Hawk's undergound

Thought that some people might want to know.

(60fps 2D games are generally fine as well.)