I did a reset of Win10 last night. It went well, fairly fast, and kept all my personal files as advertised. It wiped out my Office 2016 preview, whcih is fine, and Office 365 is working fine. Scrivener is working again as well. However, after the 10074->10130 upgrade it worked well for a few days.
I don't have any fan issues, but I may very well try Avast, just to see how it is. I've used Defender for years with no problem at all, but I'm a 4GB machine, so if it also saves memory, I'm all for it.
I have yet to do any sort of battery test. I rarely even try to use battery more than an hour or so a day, so I'll have to try it over the weekend. One difficulty I have is I really dislike working on the screen when it's below 75% brightness, and I know a lot of people like 50% or even less. I'm sure screen brightness will affect my results some.