Are nightly CyanogenMod releases safe?

I am using a 2013 Moto X Developer Edition (XT1053) and am currently running stock Android, (with the exception of Motorola's software) and I am thinking of switching to CyanogenMod. However, after looking at the [CyanogenMod download releases for the "ghost" model](http://download.cyanogenmod.org/?device=ghost&type=) , I notice there are pretty much only nightlies. I have never used a nightly release before, and I do have a nandroid backup if anything goes wrong, but are the nightlies stable enough to use daily?