I've used rockbox a lot during the last months since i got cygwin, and i'm very happy for it.
Before Rockbox i used IPL, and when i installed Rockbox, i checked the IPL wiki, which said that Loader2 _supported_ rockbox.
And it works fine for me.
But i've seen some talk about that it doesn't initialize the coprocessor and so on, is that still the case?