They're pretty different devices... but here goes.
Screen: Unless you really love AMOLED, the 5X is better
Processor: Very close and very similar, I give the edge to the 5X
RAM: 6 has more
Storage: 6 has a 64GB option, if you're looking for only 32 no difference
Size: nexus 6 is huge, i love it. 5x is much more manageable
Feel: the nexus 6 feels stronger, but the 5x feels much nicer
Fingerprint Scanner: 5X wins
Camera: 5X wins
Software: both Nexus, but 5X wins because it'll be supported for an additional year.
Battery life: 6 wins for "heavy users" but 5X did very well for the time I had it. Both easily blow through a "normal day".
Out of 10 Categories: Nexus 5x tied or won on 8 categories. Nexus 6 tied or won on 5 categories.
Of course, not all categories are equal. If it were me, today, I'd go 5X. I only had one for a few days but I really, really, really liked it (replaced with the 6P because I like bigger screens and 64GB).
I disagree with most of what you said.
SCREEN: the amoled screen of the N6 is beautiful, and 2K. How you can compare an LCD 1080p to it, I don't know.
CPU: 64bit means nothing if the software is 32. The 805 runs @ 2.7 which btw, is the highest clock available right now. Speed test show the 5x is laggy and isn't even in the same ballpark as the 6.
RAM: nuff said.
Fingerprint scanner, well the N6 doesn't have one so......
Camera is better on the 5x, but the 6 is no slouch either. I take awesome pics and vids with my 6 and I have OIS.
I'm not saying the 5x is a bad choice, but unless you NEED a fingerprint scanner and "better" camera, I don't see how you can say the 5x is better.
As far as updates, the 6 will get the next major update (N), and you can get 2 more major updates after that if you want to run a custom rom. By then no one will care to use the 5x or the N6, so....
The 5x wasn't meant to be a flagship device. It's an upper end midrange phone. The N6 can still keep pace with the best of 2015. The 5x can't.