What's it like now?

Hey everyone, i'm in need of some advice. I currently have an iPhone 4s and iPad mini, however, after iOS 7, my iPhone adapted to it but iPad doesn't seem to do so. So i decided to sell it since i don't use it nearly as much as i did before anyway. I wanted to sell them both and get the iPhone 5 but I'm looking at the HTC One as well since i was a long term android user before i switched to iOS. What was bothering me about android was that it always had lag, no matter how good it's hardware was, how many things u did, there were always some instances of lag that my 4s, now a 2 year old phone doesn't have. Nearly perfect and constant fps and premium build are things that keep me with apple but One seems like it could match iPhone 5 in those terms so i'd really love to see some first hand advices from someone who has it and knows how an iPhone works. All the reviews boast about how they hand intensive games and such, the stuff people use their devices for 5% of the time while no one seems to talk about everyday performance and fluidity, and while checking a GS4 at a local store i encountered some scrolling lag which is embarassing for a 600$ smartphone :/