So far I am liking my Moto X more than my Nexus 5. Feels better in the hands, has some extra cool features, and better battery life.
The first two pictures are from my Nexus 5. The second two are from my Moto X. Usage from the screen shots might appear different, but that is only because on the Moto X, I left it unplugged overnight right after charging it completely. So in relation to SOT, usage patterns are still similar.
With the Moto X, I can get longer standby and longer SOT. Plus I like the feel of the phone in my hands much better. And active display and always listening are some neat features to have. Ultimately, my biggest reasoning for buying a Moto X was for battery life. With that, I am so far pretty happy.
I know other people say "oh you are doing something wrong blah blah blah." And the reason that argument comes up is because people try and compare the battery life of their phone with the battery life of someone else with the same phone. And those two people won't have the same usage patterns or all the same features turned off/on. More importantly, they won't have all the same apps installed. And some apps will keep your phone from going into deep sleep more than others (this is an issue I have run in to). I think these screen shots show a lot more because they are both from similar usage patterns.
If you use your phone more, your battery will die sooner. If you use it less, it will last longer. That much won't change. But this gives a more objective look as to which one, as a whole, will last longer. And I think the Moto X is a clear winner. But that really shouldn't be a surprise to anyone considering all the optimized hardware it comes with. The AMOLED screen certainly helps, GPU handles less pixels, half the amount of cores, other optimized cores for certain tasks, lower clock speed, etc.
Overall I am happy with my purchase. Very happy that I got it for the same price as my Nexus 5! It feels just as speedy as the Nexus 5. I am sure if they were held side by side there would be a slight difference. But obviously that won't simulate real world use. Real world use is using it in the real world and having it feel snappy. Plus I like the speaker better. Camera, eh, not so much. I enjoy my Moto X and am considering selling my Nexus 5 now. Might keep my Nexus 4 as a backup.
For those who care more about numbers than real world use, go with the Nexus 5. For those who care about speedier updates, I am not convinced the Nexus 5 has a huge advantage. It took weeks for my Nexus 4 to get the 4.4 update. Before I got it, I saw reports of 4.4 for AT&T Moto X. So who knows what this will be like in the future. If battery life isn't an issue and you are looking for a great camera, don't look at either. If these are your only two options and you want the better camera of the two, it is, IMO, clearly the Nexus 5.
I didn't plan on this turning into a mini comparison/review. I know a lot of things are subjective. The thing that I was really looking for was battery life. And I think it is pretty objective, the Moto X will last longer.