I'm undecided. Had my xz since UK launch and I'm disappointed with the rear panel raising up (need to discuss with my network ref a repair, but I know it will keep happening) and the camera can be a mixed bag. My other half has an HTC one, like it a lot.
Anyway, the xz. Glad to know the op is pleased with it.
I'm considering the new nexus, should be details in a few days
A backup is one of the best things you can do .. If you don't then your set to fail , so remember .. be very careful out there!!