I installed 10581 too. This one is finally good, now I have windows 10 in daily use in Ativ S. I can even talk WhatsApp calls wia bluetooth in my car. Yeah! Normal, built-in camera app don?'t take good pictures. I use ProShot because focusing and taking a photo by touching works nice.
One hard reset from Windows 10 was necessary.
Everything works, great. There is a lot of unnecessary operations, which consume power.
Windows 10 uses a bit more power than the 8.1, but only a little. Anyway, I need to recharge the battery every night.