I'm an iOS developer and while I agree iOS devices tend to be smoother overall saying there is no lag is just wrong. Loading Spotlight on iOS < 7 is a good spot to force just about any iOS device (except the iPhone 5) to noticeably lag, and it isn't the only consistent source of lag.

That aside, Samsung is the most successful company with the worst design aesthetic I can think of. I don't know why people buy their devices, even if one is an Android fanatic there are devices that lag less and look much better at better prices. I'm shocked they are doing as well as they are.