I'll put this way, don't expect 5.0 to be the version of Lollipop that many OEM's ship with. Expect to see a 5.0.1 before January, seriously. ICS eventually got stable at 4.0.3, JB was 4.1.2, 4.2.2 and 4.3.1. KK was 4.4.3/4.4.4. The main reason for this, is that Adobe Air apps are completely incompatible with 5.0. I believe this is because they can't run on ART and thus the OS throws them away during the upgrade. Then again, why the fuck anyone would use god damn Adobe Air is beyond me.
In regards to Volta, it does seem to be helping somewhat. Battery scheduler features are working better, but we'll have to wait for major battery drains (Play Services, GMS) to actually be updated to take advantage of them. With Google, one team implements the tools, the others update the apps... Things take time to trickle down.