Finally got it installed, after what seemed a long long wait.
It’s been a good little thing, I’ve never had a single problem on it. At least not a serious problem, I think that I had to restart it once since something didn’t work but that I see as “fully normal”.
Let me start by saying: don’t expect miracles from it. Sure, it’s pretty nice and brought some cool things. But, it’s not the gigant leaps that earlier android version brought. It’s a nice step though.
As with Android 4.2 and above Developer Options are simply hidden under Settings.
Some say that HTC One doesn’t fully do Wifi Direct but it does, it just lacks the app for it. Which means that it’s rather easy thing to fix really.