I think I'm in the minority, but my family had lunch at Coral Reef when we were at Epcot in September, and it was excellent. Service was good, food was tasty.
I had the Chocolate Wave and it was incredible. I would recommend it.
It's probably not romantic, because the seating is all open, but it is dark, for what that's worth. Most restaurants at Disney are kid-friendly, obviously, so if you're going for an adult-only atmosphere, try one of the signature restaurants at the Grand Floridian.