with nightly's you will need to overwrite everything.
I use nightlys on my 600D as its my play camera, i have a mkii for main stuff, id say its personal choice, if something is up with something in a nightly build like autoexposure is atm then if i need i use 1%'s build as it works and the build is stable, personal choice at the end of the day and what you want to be doing.