14939 had bad battery issues. The 15000 series is way better on the battery. 15043 looks to use more battery than 15025 but it's ok. I wish I could have just stayed on 15025. However, 15031 & 15043 are not good at all SO DON'T go that far using the Fast Ring. I suggest you use the Slow Ring because Mathew above says Slow Ring only took him to 15014 which was a decent release. I really doubt Slow Ring will ever allow 15031 to install as Slow Ring is supposed to only allow releases that Fast Ring has tested and approved as good releases. I'd think the next Slow Ring update won't be until 15031 issues are reasonably resolved so will skip forward to a decent release once it's found.
Now for the good/bad news. I have found a somewhat cumbersome help with the BAP battery drain issue. When I did the hard reset and installed my backup, when it got to the point of reinstalling all my Apps from the App Store, I deleted BAP before it could even install. It is still noted as being on the phone, probably forced by the SIM card as a required Verizon App, as it tried to download the BAP Store App but by not allowing it to install, it fixed my battery drain issue because although I can see BAP on my battery use; it's <1 as it has no software to run it. But, I also had to put my Store Apps on manual update as it tried to update BAP on it's own as I had Store set to auto-update but I caught it in time. Thus, I now have to periodically update my Store Apps "manually" and immediately delete BAP before it can even download. It's a little bit of manual work but looks like this is a fix for now. No excess battery drain since my hard reset and I was just on the phone for an hour and BAP never started up to kill the battery (BAP use to start up during a long call and kill the battery).