Just updated to WP10 last night. There has been a learning curve, trying to come up to speed on where to find features, how to get things working that weren't. I'm going to stick with it for a couple of days at least, and give it a shot as a daily driver.
And back to 8.1. I enjoyed the look and feel of WP10, but it was just a little too unstable. The biggest thing was when I'd turn my phone on, and go from my lock screen to my start screen, it would sit for 10's of minutes with "Loading ..." on the screen. I tried turning off / on, battery pull, soft reset, it would still happen.
The apps were pretty stable, once I reloaded them from the store. However there was a constant set o apps trying to download, even though they had already downloaded and were functional.
Scrolling between inboxes was a pain, I hope they fix that for the released version.
Anyway, back to 8.1, then the updates to version 8.10.15137.148. Some shuffling around of tiles, reloading of apps, and I'm back to a stable phone. Loving it!