I have a problem in this area and it has prevented me from moving back to Firefox. If I run Firefox on my 13" MBPr with the panel resolution (Scaled->More Space) then the battery usage goes through the roof. I'm following https://bugzilla.mozilla.org/show_bug.cgi?id=1404042 and hope this issue gets fixed soon. It seems that Apple changes may have made this issue more apparent to users in general.
I can obviously follow Bugzilla, but does Mozilla have anyone working this from more of a support angle and provide high-level updates on the top issues like this?
On some of them. I use Mac with non-default resolution and I have no issues.