I think in my opinion that it is MUCH easier to work with a PSP than it is with a DS or DS Lite. For example, in order to run an emulator you have to buy a $200 4GB HUGE "memory stick". But for the PSP, you buy a small high speed memory stick for the same price and capacity. It is also much easier to add homebrew to the psp using the USB cable. For the DS you have to buy a special cable and the interface is very confusing, not knowing where to add the homebrew files.
Lets not forget that the PSP can do almost EVERYTHING that the DS can do (homebrew) and even more. In conclusion I think that it is much easier to work with a psp than it is with a DS or DS Lite when it comes to homebrew, emulators, and ISO loaders. Who agrees with me, disagrees with me, and why? Thanks!
Please don't flame, i am just giving my personal opinon and i have nothing against the DS or Nintendo