Did a little experiment to see my Nexus 5 against the Z3 and Z3C seeing as the Nexus 6 is far too big for me.
Leading heavily towards the compact as i've often felt the N5 is a little too big for me sometimes. Only thing i'd prefer the Z3 over the compact is bigger screen for PS4 remote play other than that I prefer the compact.
Doesn't matter too much as I won't be getting a new phone until next year anyway, the Z4 / C will probably be out by then anyway.