I have been asking myself this question a lot lately.
I'm loving my One, but I've had to work really hard to get the battery to something even half way decent. I'd love to play with an X for an extended period to see how much different the ergonomics, speed and screen quality are for me.
But it sounds like all of the X converts are very pleased. Either way, I'm sure you can't go wrong.
OP - I realize that last bit I wrote wasn't actually helpful in any fashion. My apologies.
However, you said you're mainly concerned with battery life and data connectivity. I think with that being the case, you'd be happier with the X. By most accounts, battery life is phenomenal with high screen times, and the Motorola Radio's are typically some of the best I've used for signal and speed.
Don't let the specs on paper fool you either. Even though the X has a 720p display, it's still a fantastic screen. Also, just from playing with a couple of the X's my friends own, it's one of the most comfortable devices I've held lately. And the X8 architecture seems to be about as responsive as my One in most every task.
The X definitely has things well figure out from what I have seen and with what seems to be substantially more longevity vs the One, it may be the route you want to go.
Current Device: LG G2 (VZW) | ROM: Stock Rooted 4.2
D1 | Inc. | DX | Inc. 2 | Bionic | Lucid | Spectrum | Razr | Galaxy Nexus | Galaxy S3 | Razr HD | Inc4G | DNA | Galaxy S4 | Maxx HD | HTC One