For the slim, I've read reviews saying there's not much of any performance different between phat and slim psp. I read that from IRshell 4.8, it's possible to use the extra ram for the psp browser (i doubt it does anything with the speed, but it helps reduce the cache problems). The IRshell changelog said it was some kind of class/method within some homebrews. So far, I know that most homebrews (excluding the ones built on 1.5kernel) work on the slim. But which homebrews actually take advantage of the ram?