Re: maps, you can revert to "classic" by clicking on the gear.
Anyway, for the longest time - even with a bare browser (no extensions) - YouTube wouldn't save certain settings (annotations disabled, video quality), even while I was logged in.
It's so nice of Google to give their users so much advance warning of incoming suckage. I guess that's part of the whole don't-be-evil mission statement. Kudos to them.