I just turned mine in. Great phone, barely any problems... but barely any excitement out of it. Besides the wide lens (with the ensuing lower-qual pictures) and double tap to wake/sleep which I still try to use in every device I touch, nothing else wowed me. Yeah, the DAC was nice for a while, but then it's not so great, especially because you have to be tethered to the phone to use it. Go BT Headphones!
Add the fact that it's almost December and the phone has the security patch of a couple months ago, and it just made things worse.
Oh, and the 'forced' heads up notifications also killed it for me.