I started using Nightly for kicks and giggle around 6 months ago and my about:crashes shows me only 6 crashes (none of which were able to kill anything more than a tab (and in all the cases, the offending website was YouTube)).
Nightly is amazingly good even if it is built from the HEAD of the trunk (branch in git terms).
Nightly is amazingly good even if it is built from the HEAD of the trunk (branch in git terms).