2013 Cadillac ATS here and bluetooth works pretty well. 90% of the time it's flawless...other 10% I have some issues that might require disconnect/reconnect.
My car has built in Pandora support and a touchscreen where I can control what's playing: thumbs up/down, next, play/pause, album art / song info.
Also non-Pandora seems to work pretty well as I am just now switching to Google Play Music All Access...can control it well with the touchscreen also: next, previous, play/pause, song info.
Both can auto play when I enter the car - no need to do anything.
Also no problems making/receive calls using the touch screen or steering-wheel controls. I don't really use voice command at all though...not my thing.