There is no question - the Air Canada product wins hands-down.

Superior Lounge (MLL)
Free overnight hotel (if your connection in either direction requires an overnight stay)
Pod-style lie-flat seats
Inflight food has improved tremendously
Great inflight service (and you can learn a little French along the way)
Seamless connection process at YYZ/YVR
US Pre-clearance on the way back makes your US arrival quick and easy