Heard it Monday on radio 1 without knowing who it was and thought "this is good, sounds familiar, I wonder who it is" and was surprised when they said who it was. I've heard it a few time since and think it's great. Reminds of something - somewhere between Oasis's Stop Crying Your Heart Out, something by Pete Cetera/Chicago. the vocals are excellent, particularly on the chorus when he doesn't sing in the high voice, and the backing track if guitar and strings/choir works perfectly.
When they first came on the scene I wouldn't have expected to be saying this but One Direction made some great (if derivative) tunes and all the solo efforts of the 1D members have been pretty good.