Just so you all know, I'm only really posting here because I want to see my new image next to my name... hee hee!
Uh... Anyway, I don't know if this is still the case but the University of Minnesota used to be well known for recruiting high school tight ends to play offensive line for them. They were a bit smaller and lacked some strength but when running the ball -and especially from sideline to sideline, as UM did (does?) frequently to set up the play action passes- they were perfect and oftentimes posed a real match-up problem for defenses. Their quickness and agility was great on pitches, tosses, options, etc but also on trap plays and in general gave them the ability to have a very fluid, moving offensive line.
The only bad thing was the QB would get lit-up when they were down late in the game and he had to just drop back and throw downfield (which, lets face it, is 80% of the time for the golden gophers).
BYU almost guaranteedly benefits from having a much bigger, more set-in-place offensive line because their offense is much more based around 3-5 step drops and downfield passes. Even when we do run, frequently it's a draw-type play, in which case it's also beneficial to have a bigger, less-fluid offensive line.