Yeah... It allows players, specifically the QB to do less thinking... Why don't you check out this video (skip ahead to about the 7:15 mark and start watching and then try again....
YouTube - Texas Tech's Mad Genius
So, his QBs have to get a pre-snap read like every other QB in every other offense from high school varsity through the NFL...
The biggest difference with Leech is that he would spend upwards of 80% of his offensive practice time running pass plays to allow the QB and WRs time to learn the reads, timing, etc and be able to do them simultaneously and flawlessly on Saturdays. Most coaches won't allow that amount of time to work on one aspect of the game, so the ability to read all of that information in 2-3 seconds before the snap isn't possible. It isn't really complicated, but it's different so it seems complicated.