I have a CycloDS and couldn't be happier with it. It is THE fastest updating flashcart for the DS available, looks sexy, has awesome designers, AND a very, very friendly forum. To update, you just copy the update file to the root directory, pop it in the DS, and let it go. It deletes it and everything for you. Its the most user friendly IMO.
Of course, I only have backups of games I already own, no illegal roms or anything. Thats illegal.