I tried both a 5X and Z5 today, out of curiosity.
I don't really like the 5X build quality. The build being the same as the original 5 is a lie. It's more plasticky and doesn't have that rubbery feel to the back; the buttons are just plastic and not ceramic. What I really liked was the screen on this - Seemed color accurate and with good enough colors. Couldn't try how it performs, though, as some guy decided to put a random lock pin on it at the store I went.
The Z5 is beautiful. Loved the materials, and the phone seemed more light than my 6S. The feel of the frosted glass is really nice in hand. Screen is cool on this, too. Was disappointed to see a micro stutter on such a price-y phone, though, when I opened the Settings app and scrolled down right away. But that probably was just a thing of the moment and doesn't happen much.
Hope to try the 6P one of these days.
Ah forgot that I tried the X Play too and the first thing I noticed was how high the software dpi were. Don't know what's the deal of Moto with having the dpi so higher than the displays. Same thing with the Nexus 6, but probably only Google fault. The E, G and 2014 X are fine.