Just wait it out.
In a few weeks you'll get an OTA notice for an update.
Why, exactly? I'm very happy to have flashed the new preview, it's awesome. Last time I went back to KK after a while, because there were just a few too many things that didn't quite work properly in that first preview, but this time I've found no such issues so far (except for lock screen media controls, which are currently not quite what they should be - but that might be because of API changes, meaning apps need to be updated for this to work right again). So unless you really don't want to wipe your device, I say go for it. This is much nicer than being stuck with KK for another 3-4 weeks. Of course, not everyone is as impatient as me with this stuff!
Works fine but there's a battery issue that'll be solved in the next preview, so I'd just wait it out. A random miscellaneous stat is draining more battery than screens. Otherwise, it's nearly flawless.
Are you taking about the Misc battery drain? Yeah, that's a tad annoying, but I'm not sure it has any actual major effect? I'm currently at 54% battery with well over 2h of screen-on time. That's better than the average on 4.4.4, I'm pretty sure? I did turn off NFC, which some have said makes Misc drop quite a bit. Maybe (hopefully) battery life will be even better in the final release, but that isn't exactly a convincing reason to stay on KK.
And what next preview? Have you actually read that there will be another one? Seems rather unlikely to me, as the final release is only 3-4 weeks away or so.
I'd easily recommend anyone who doesn't want to wait to flash the preview. It seems to be feature-complete, and everything works great.