yeah, the ram difference does matter buddy. Due to the lesser ram on the phat، the loading time for games is much more compared to the slims or brites. Some emulators and homebrew even refuse to work, due to the lesser ram. I say, if you can get your hands on a hackable slim، its the best psp currently. Even more better if you can get the original slim as it can softmod a battery, but its very rare.