From what I understand, Samsung's abomination of a OS skin is the only thing that lags.
My HTC One lags about as much as my iPhone 4s did with the latest iOS update (got rid of my 4s about a month ago). Which is barely ever if at all.
I can't speak for any other phones. But I know the Galaxy S4 I tried out at the AT&T store was a laggy POS.