I was happy with the results too, but wanted to try different approach and compare them. I am writing down ratings of my players in FA matches. Old guard had ratings approximately 0.2-0.5 lower than fresh meat with whites trained equally (same positions compared). Not a big difference for 16 games though, could be just random fluctuation. I will continue to track ratings.
"Equally" means I use only clean drills, I train only main position even if player has several positions, and I don't train "leftover" skills -- never gray skills.