Earlier versions of the emulators had varying problems with lag and sound quality which, little by little, were alleviated with each new release.

As far as we can tell from the translations of the text, NJ realized that unzipping the cache files of games into a folder with the same name would basically remove almost all the lag in playing any of the said games. Yes folks, that means near-perfect emulation for all three programs... at the cost of using up more space on your PSP.