Build quality is better on the moto X? You my friend are way off here! The build quality on the X is just absolutely terrible, it feels like a bad Fisher Price toy with uneven panels with some sides being rough and some being smooth, wobbly cheap buttons, and Yea a pretty inferior screen.
The 3 things I just mentioned have been mentioned in a ton of articles when the moto x is described. Does that make it a really bad phone? No not in my opinion. Its been some people's top phone of 2013, and that's cool, everyone is entitled to their own decision. But yes once we break into 2014 those moto X specs will be very last generation.
And the build quality on the N5, especially the black version, is just much better built then the moto x any day of the week. Unless you have tiny little hands, then of course you'll favor the X because of the bigger footprint.
Also yes I switch devices very often, I may go through 5 or 6 devices while someone else is still rockin the same device. But that's just me, I don't boast about it, that's just my thing. I like the moto X, and think its a pretty fine phone with a lot of strengths, however I ended up with a well made nexus 5 unit and wouldn't entertain going back to the moto X...Again just my opinion, if you feel otherwise, that's your opinion.