Let me preface my comments by saying I've had roughly 20 minutes with the Nexus 5 so my thoughts/opinions on that device would not hold the same weight as others who have either reviewed or owned the device. That said, I'm confused on the disparity in reviews as it pertains to the camera/screen/battery/speaker. Those that have reviewed it so far have probably used the phone for 3-5 days; in my experience, that's enough time to get a firm grasp on the device, especially if your job over that span is simply to use the phone. With that said, there seems to be some differing views on those aspects of the phone, although outside of the screen, these were expected to be areas of issue with the Nexus 5.
Having both the Nexus 5 and the Moto X (Verizon, running the new apks from 4.4/Google Home) in my hand, I really wanted to see if there were any huge, glaring differences that would make me want to use a Nexus 5 over my X. Honestly? There's really nothing about the Nexus 5 that appeals to me over the Moto X. There's a negligible difference in general performance, which is pretty amazing considering the advantage of not only the more powerful chipset, but the optimized 4.4 OS. The screen on the Nexus 5 looked washed out compared to the Moto X, something I didn't expect. I came into this thinking the screen was going to be the big sell and it really isn't. It's still a great screen, but not as great as I expected. I wouldn't dare leaving the brightness above 20% on the Nexus 5 for fear of not even getting 6-8 hours of use on that battery. I don't have that problem with the X. Speaking of battery, I can't really comment on it with 20 minutes of use. All I can say is that if I was betting man, I'd bet on it being pretty subpar. You don't add a 5-inch, 1080p screen, a higher clocked/more efficient CPU, and LTE with a 200 mah bump and expect anything great.
From the stills I've seen and the specs, I'd say the camera is better on the 5, but not in such a way that makes any real difference. They're both pretty bad, but Moto made the camera app updatable through the Play Store and that goes a long way with me. The speaker on the Nexus 5 was pretty awful compared to the X, in both audio/video playback and a test phone call on speakerphone. As far as the software goes, 4.4 is coming to the Moto X. It's coming to the Moto X while still maintaining Touchless Controls and Active Notifications. There's nothing specific to the Nexus 5 that gives it an advantage on that side.
Long story short, I'm not that impressed. I wanted to be, but I'm really not. 4.4 is a step forward, but not a huge one, no matter how much people want to be convinced of it. Active Notifications changed how I interact with my phone every time I pick it up. Touchless Controls changed how I interact with my phone when my screen isn't even on. -That- is innovation and there's nothing about 4.4 or the Nexus 5 that even touches that. When you throw in the fact that even with the all the hardware advantages, the Nexus 5 doesn't really outperform the Moto X, there's not much else to say. In my opinion, and I know I'm not the only one, the Moto X is a better phone than the Nexus 5. I know the Nexus line is the "hero device" every year and it's borderline blasphemous to say such things, but there's no shame in losing to what would probably be the phone of the year for 2013: the Moto X.