Overall it's sort of a mixed bag for me. I think the 6 is a very impressive phone, but it just doesn't do it for me. I think that if it were the new $350 Play Store phone, I'd probably jump on it, but at $650 or under contract it just doesn't appeal.
That's how I feel. I might buy a T-Mobile US version of the Xperia Z3 or just keep my Nexus 5 a while longer. I would like to see how Android 5.0 feels on it first.
To me, Moto X for
$450 with a .edu discount is much more appealing than the Nexus 6. Since I'm on T-Mobile now, The branded Xperia Z3 with Wifi-calling and LTE band 12 is more appealing still. The Z3 has the added benefit of being a reasonably sized phone. I'm not saying I won't ever get the Nexus 6, but it's the first Nexus I didn't immediately want without seeing it first in-person.