well the 64bit architecture is nice to have,
but I'm sure it will take some time until Apps really take advantage of it. (at least if i compare it to personal computers. a lot of endconsumer software still hasn't full 64bit support)
everything should run quite smooth though if it's well optimized
720p video recording at 120 FPS:
that's just a gimmick. it won't take long until this becomes a standard for every smartphone in this price range.
fingerprint sensor:
it still sounds more like a gimmick to me than a real security factor.
Could make more problems than it solves and it's defintively no reason for buying with the NSA case in mind.
besides...
They still haven't integrated a microSD-cardslot, right?