For ref: I have my 10gig hd (with the retail dash) stored safely away. I also have on my pc, a folder with all the files from an ndure/xboxhdm/unleashx install for backup purposes, inc eeprom and hd data etc...
In my xbox I currently have a 40gig hd running xbmc as my dash replacing unleashx in E:/dash (no shortcut to apps folder, though I do now have the shortcut and cfg to do this) and confluence as skin.
I'm happy with the set up and probably won't ever update the dash as it does all I need.
I just play a few legacy games, and occasionally use the music player for the visulisations on a big screen. I won't ever need to go back to retail dash, ever. I always boot into xbmc from either pressing start or eject.
What I want to know is, taking the above into account, what files can I safely remove from the xbox so I just keep the xbmc?