Psp 2000 speed vs psp go's speed? Help me decide to get the PSP go OR stick with the 2000.?

I have a question. I think I am going to save up and by the Psp go because of the portability factor. I already own a psp 2000. But i only have a couple UMD's. So the UMD factor does not count. The thing i am worried about is (1) graphics and (2) the speed of the game. I want to know if the go will be more crisp since it is on a smaller screen. And the MAIN question! Will the games on the go be slower or laggier since it is running off the memory. Or is it the other way around because it has to read the umd. And the does controls on the go fit the hand nicely? NOTE do not say "just stick with the 2000 since you can hack it"! I have no use of hacking it and have no reason to.thanks for all the answers!