Highly OT, but is there any glaring difference between FF Dev edition and the stable version? AFAIK, all the devtool features are same in both the versions and I did not find any glaring difference as such.
Dev edition is the same as beta, except occasionally (not often, as far as I can tell) some features in development are enabled slightly earlier. In other words: it's beta but with different branding.
Dev edition also makes it easier to run both Firefox stable and a non-stable install since they default to separate profile folders.