Thanks all for your great responses. After spending time playing with both phones yesterday, I purchased the S4. I can't give a specific reason, it just felt right to me.
After sleeping little last night from playing with it, I am loving it more today. Gorgeous phone and remarkably easy to set up and use, coming from years of iOS. I find it very intuitive and it even automatically connected to my AT&T MicroCell and has maintained the connection with NO drops, and consistent 5 bars. I had constant disconnects on my iPhone 4S which is why I decided to make this switch.
Enjoy your One. It is a fantastic phone as well. We are lucky to have great choices now!
Yep I've been saying this there really is only a hairs breadth between the handsets as they are both killer. There are compromises or arguments for & against both - but at the end of the day they are both fantastic phones.
What it will boil down is to personal subjective preference. How it feels in the hand, the colour, the weight, etc...
Just as we all don't buy the same clothes, the same car, the same food. Personal taste has to play a big part on what device we buy.
The iPhone 5 is fab, but just as much as the S4 & the One and I'm sure the iPhone 5S will be great too. So yeah choice is great, and really its very good for the consumer tha there isn't one that is better than the rest because it drives them to innovate and improve going forward.
We are reaching a point where hardware in our phones will probably plateau out, so software and refinements will be the way forward. Its interesting to see to companies approach the software side very differently one with emphasis on refinement and coherent user experience and the other with features, and niche apps. Again what is better is just down to the individuals tastes. At end of day its all good