Well, I've been looking for the perfect Android phone for me this year. I've owned the Note 2, the GS4, the Nexus 5, and am now using the HTC One. No interest in the Note 3, because it's too huge and I struggled with the Note 2 for almost a year before deciding I was done with the huge phone. Each was bought and sold again on Craigslist where I can manage to try them all without the long-term commitment.
The GS4 was frustratingly laggy, and I'm so tired of the Samsung Touchwiz nonsense. Battery life was less than stellar. I think I'm done with Samsung for awhile.
I tried the Nexus 5 and was unimpressed by the screen (since I was currently using the HTC One) and the battery life was unimpressive, to say the least. Overall, the phone felt cheap and too light. The camera was a mess, in my opinion. Maybe it will be fixed eventually, but I didn't have the patience for it. Really wasn't the phone for me, as I didn't feel it was an upgrade at all. Went back to my HTC One.
For the most part, I really like the HTC One, but ergonomics are awful. Hard to reach the power button, and the volume toggles are difficult. Though some may like the "ultrapixel" camera, I personally HATE it. It's far too wide and any people up close are horribly distorted. Makes them look fat and short... like a carnival mirror. Panoramas only work when the camera is held horizontally. The flash is unusable, not that I ever really use flash on a phone. That being said, the screen is gorgeous, battery life is acceptable, and I tend to like HTC Sense. It's been a nice change from Samsung.
Went to an AT&T store and was impressed by the Moto X, which surprised me. Loved the screen even though it was 720p (I couldn't tell the difference). It was snappy and felt just right in the hand. Today, HTC announced Kitkat by the end of January. Seriously? So I logged into Ebay and bought a mint Moto X 32gb that will be here soon. I'm expecting to be satisfied finally until next year's crop of super-phones start appearing. This article has been pretty much my observation, as I'd rather have the whole experience, rather than one or two excellent feature with lots of compromises.
On the other hand, I'll keep my HTC One for a while, just in case.