Why do I want a Nexus 5X? Besides timely updates, latest vanilla android, and all that awesome stuff, I'd say because it's a dev phone, it is the benchmark for everything else out there. So there, I NEED A NEXUS IN MY LIFE!
I want a 5X because my N5 just got drenched at the F1 race in Austin (it was quite monsoon-y). I'm using a ZTE Zinger while awaiting my N6p, but I'm not sure the size will be acceptable, and I'd love to have a 5x to compare it to!
I really, really want a Nexus 5X because my Nexus 4 is getting old and I really like the new camera. I won't miss smart burst, 240 FPS slow-mo and EIS, so I really like the Nexus 5X.