HTC ONE. This is a tech forum with tech people and I don't see how some of the advantages play out in the coming months for the other two phones. IMO of course.
GS4 advantages over the ONE: Faster processor? Well its the same processor clocked to 1.9 vs. 1.7 GHz. I've read reviews already that say the interface on the HTC ONE is more fluid. Is this because of Sense vs. TouchWiz? Unclear but I do know that the HTC ONE can be unlocked right out of the gate and all you need to do is clock your processor to 1.9 if that extra 200 MHz really matters to you. May not be something everyone does but again, this is a tech forum and a lot of us are going to mess around with that.
SD Card slot: Understandable to a certain degree but this is not an issue for me. I already have 20 GB of storage through PogoPlug free for life (check CNET for that promotion) and you also get 20 GB through DropBox in a promotion with HTC. Add on the 5 GB you get from Google Drive and the 5 GB I already had through DropBox and I have 50 more GB on top of the 64 GB of my HTC ONE. I prefer to have a lot of things like Pictures and videos on the cloud any way. This is a non issue for me in this day and age.
Removable Battery: Understandable but I imagine if I really want to swap out the battery because it goes bad before I upgrade again in 2 years that I can. I upgraded the iPhone 4 battery in 10 minutes and it was a cake walk even after being voted one of the more difficult devices to do it with. Besides, I again find it unlikely that I'll need to replace the battery before I replace the phone all together. There are definitely some real world issues regarding this but not for me.
Nexus advantages over ONE: Vanilla Android with updates as Google releases them. This is pretty good if you are the average person who prefers stock android, but what average non-techy person is going to care about vanilla android? Again, this is a tech forum and I myself will be unlocking my bootloader pronto and installing custom ROMs as soon as they are mostly prefected for the ONE. We will have 4.2.2 on ONE via the custom ROM community if not directly from HTC, so this is a non issue for me. Part of my appeal to Android in the first place is playing around with custom ROMs and Launchers so I will be doing a lot of it.
Bottom Line: I think the advantages on the ONE far out weigh the advantages of the other two because there are ways around most of them. Processor clock, cloud storage space, mobile battery if needed, etc.
On the other hand, there is NOTHING you can do about a cheap looking piece of plastic trash. You can't make it metal. You can make the metal plastic with a case. That anand review and others have already said it best. You also can't do much with the speakers if you use speaker phone regularly as I do. Those two things set the ONE apart much further then the other things that supposedly set those other two apart.
"I always start with industrial design and aesthetics, probably because its the most obvious superficial thing that hits you when picking up almost anything for the first time. With a smartphone thats even more important, since theres so much that revolves around the in-hand feel. I pick up my phone too many times a day to count for better or worse, thus the material quality and in-hand feel really do make a big difference."
"The HTC Ones fit and finish are phenomenal. ... In my books, fit and finish goes, in descending order of quality, metal, glass, and finally plastic. Or instead of plastic, polymer, or polycarbonate, or whatever overly-specific word we use to avoid saying plastic.
"Its the kind of manufacturing story that previously only the likes of Apple could lay claim to, and the HTC One is really the first Android device which reaches the level of construction quality previously owned almost entirely by the iPhone"
That last bit sums it up best for me. I've been an iPhone user namely because of this. And also because the android community makes ridiculous claims that the iPhone isn't open and there is so much you can't do on the iPhone. True for a stock iPhone as some of these other things are true about stock Android devices. But again, this is a tech forum. I can't be the minority here who is hacking everything I own. I actually have found already something I can do on the iPhone that I've challenged the android community on this forum and around the internet to explain how I would do this on an android device with no answer given. As best as I can tell, it can't be done on Android and is a regular problem solved by people in the iOS jailbreak community.
But I digress.
HTC ONe is the ONe for me and I'm quite happy with the decision.