I know that there is a lot of information going around that debugging PPC over USB is very very slooow which is exactly what happens to me also, but a friend of mine has been able to get his running perfect on his throuh USB2 without any slowdown and this includes even my PPC.
I'm unsure how he's done it, and even he's unsure how he's done it.
The only difference i see is that i'm using Win CE USB Driver and he doesn't have that on his machine, he's got a lot more different types under his USB Controllers but which one works better i don't know.
Has anyone else come across this, if so then please let us all know the secret

Cheers