Now I did.
In short, the S4 is just another Android, but with more (quite useless, or ill functioning) gimmicky sensors. And low storage.
Only new feature I found useful was the swipe over to answer. Still, I usually find a clean finger (or a couple knuckles) to deal with any situation...
And just like its predecessor, it's easy to slip from your hands, camera may be just "good enough" but the software sucks, buttons are easy to press by accident (side and touch - option and back - ones) and the tear-off back cover is still a terrible idea. Oh and the low storage... on a device that wants to "sell" specs and hardware?
I guess reviews like this are spot-on:
http://bgr.com/2013/05/08/samsung-galaxy-s4-review-redux-software-services/
The "old" HTC One X is still a better handheld (literally) and UI experience than the new Samsung. Sense is not clutter (for quite some time now) and the device feels more solid and safe in you hands. Not to mention how simpler it is, since the already confusing "Settings" are now flooded in the S4 with new
Just look at the quick settings switches!
Considering how I love the BB Z10 grip (and UI, but that's not the point here) and how the new HTC ONE looks very much like it, I'm pretty sure that specs and hardware and gimmicks aside, the ONE is my next "best Andoird Phone in the woooorllld...."
Solidity from first contact. Usability in the long rung.
Guess that sales will tell us if people are thinking the same or not.
So far the ONE seems to be on high demand, short on stock and holding it well despite being extremely under-advertised by comparison.
Can't wait to try ONE!
(see what I did there?)