OD is the "slowest" guard training especially because it trains secondary pretty slow, and you get it only secondary with handling training which ain't that popular.
I don't believe that you recognize one 1 in the short term, i don't see it with my 2 inches but i recognize that Qualtinger reached up to Schwartz after 2,5 seasons of traing, his advance wasn't that big but i believe the 2 inches made the different betwenn then. Reichensberger was essentieally slower then those two guys, when i am training OD passing, Jumpshot, range increase at the same rate and i am pretty sure that there are no big differents in handling and driving speed(but i pretty weak in guessing secondarie ups).