I never tried for the leaves. Or the Pokedex. The Pokedex doesn't seem so hard, so far I've gotten almost all the original 150 without hacking or anything. I've gotten most Johto Pokemon too. And a few from the other regions. It just seems like it'll take some time, that's it.
But that nasty, evil Battle Frontier...I never make it much further after Palmer in Battle Tower, or any of the other brains for that matter. I've beaten them all once, but FORGET making it to them again. :/
I like Battle Factory, though! I wish I could get that one...