Start menu: I think it works quite well for the way _I_ use it ie. I mostly use the search in it to find/start programs, most of the things I commonly use I launch either from the taskbar or a desktop icon, the tiles on the right could just be removed though as I never use them and just ignore it. And I feel the search works better then it does on windows 7.
Controlpanel / settings: I totally agree and hate it, though it's not something that annoys me for daily use so that's only an occasional source for banging my head against a nearby wall.
Explorer ribbon is something I have learned to live with and it no longer annoys me, though I have to say that I'm one of those persons that have come to like it in office so I may be damaged from that.
Accessability: can't say anything about that as I have never used those features and use a grand total of zero metro apps.
Telemetry: Blocked in firewal and included in l the glaring issues part just forgot to write it.
Cortana: Very not enabled and microsoft have not insisted, may be because while I use an English windows (I refuse to have a localised version as it's bloody awful) It is set to Swedish locale and I think cortana is not available in Sweden.
I have a hard time to put a finger on what I like better with it but somehow it just feel slicker and faster to use to me.