If you're currently using the One and not missing any of the TouchWiz features, I think you have your answer. To me it'd be more about which has anything you need. If you like swapping batteries, having an SD card or any of the TouchWiz features, the S4 obviously wins. If it's too close to call aside from your concerns over obsolescence, I agree that is a legitimate concern and you should take Samsung and HTC's respective track records in that respect into account. I had high luck with my HTC device except in the software upgrade regard. They sucked there.