I am still not 100% yet, but I am leaning toward the One. I used to be hardcore HTC since the G1 and nexus one up until the EVO, and EVO3D, then samsung was slowly winning me over with the nexus 2. Then I got the GS2 and now GS3. I counted HTC out for good. Didn't think I could ever own one again..but after playing with this One I am in a tough spot. This is a good spot to be in I guess. Gone are the days of having to switch to a particular carrier for one phone. Now we got multiple heavyweights.
Anyways, I played with them both. The S4 is not that bad with the 'build quality'. Even though it is still plastic it does feel better than the S3. And is even a bit more ergonomic than the One. But I just want a sexy device for gods sake. I know that the aluminum is not necessarily better and can dent, but it feels good to hold and it is nice to show off. I perceive it as being more premium than the S4.
Next, smartphones have been my primary camera for years now. Only downside has been lowlight situations. But with the One, it blew the S4 and my S3 out of the water. I never thought I would be one to value a camera, but that is the trend. Smarphone cameras must be badass.
Having front facing speakers is very awesome as well. Gone are the days of facing my screen down so I can hear music or to make sure my alarm is not muffled in the morning, or to make sure I will not miss in important phone call. The Beats technology is also a plus since my phone is my primary music player.
The screen is also beautiful, I always loved the AMOLED with the black blacks but this is comparable and looks like a real photograph in front of me,
Never liked sense though, it seems improved. Sure I will get used to it and the button layout and all that though. And if there are any things that tick me off I hope the development community can come up with some change.