Anyone here running latest November security patch?

[Why u upside down]

I'm looking to buy this phone but since I've heard about all the Marshmallow update problems I'm really not sure anymore. I know that there have been 2 updates since and I was hoping someone could let me know if they have solved all the overheating, battery draining, performance etc. issues.
Cannot decide between this phone and an iPhone 5S now if anyone could help out.

Thanks