Like Llorean says, too many people forget that we have a lovely
manual that they can read, and then proceed to bork their players. Then when we ask if they have at least read the manual, what answer do we get? "I didn't know about the manual."
I helped a friend install Rockbox on a shiny new e260R, and from playing with it, Rockbox feels damn solid on the Sansa e200 platform. It's still got a few quirks (lack of a native USB mode being one), but what it does well (audio playback), it does it with gusto.
Fel2, as long as you read the manual and follow the instructions carefully, the installation process is a breeze. If there's a part of the manual you don't understand, then come ask us.