There has been a ton of hype and build-up to this device, and ultimately, it left us feeling cold. The S IV feels uninspired. There are small spec bumps from the previous generation and there's a ton of software which will largely sit unused. There's just no wow-factor here.
I had the HTC One with me during my hands on time, and the difference is like night and day. For starters, the One is noticeably faster in every context. When flicking between screens, opening apps, and taking photos there was clear lag on the Galaxy S IV, whereas everything was almost instantaneous on the One. To be fair, this wasn't the final production version of the S IV, and who knows which processor was in the model I had. There's a chance it'll be faster at launch.