the Sony Xperia is beautiful yet also has a rugged feel to it.
The device may feel durable... But is it really? I don't think so
I've dropped my Z3Compact three times already. Not a scuff, mark, dent, scratch, crack or anything of sorts. The build quality is amazing. Nokia would be proud.
(On the other hand, my 930 built by MM is plagued with build problems)
As for the Z line with Windows Phone, I doubt that will happen now.
There was a time Microsoft could have struck a deal with Sony to make that happen. However, Microsoft and Sony clearly didn't reach an agreement and in the meantime Sony has replaced the head of their Mobile division and sold their VAIO line to a Japanese consortium. (VAIO is actually going to launch a line of phones too, but they too will run Android).
Since then Sony has fully committed itself to Android. They've connected their Z3 line to the PS4, they've replaced the OS in their smartwatches (which was proprietary in the first two) with Android Wear and they've now announced at CES that all their 2015 Bravia TVs will run Android TV.
So as far as Sony goes, I think all dreams of having their hardware running WP are dead.
Microsoft's lack of direction regarding WP itself hasn't helped at all either, one should note.