Based on feedback and limited rental time experience:
L85s - Very very good, but less overall potential in the hands of a very good player with a good ball;
L90s - Excellent, and cunningly similar to the best you can get. They simply offer that bit extra potential across the board, and the 3 iron especially shows it's class. Talking a good player to bring it all out, and maybe some extra real time in with practice / mapping.
Have a look at some Legend Tier RGs to see what's preferred generally, and then some TL and Champs ones. The stiffer the competition the more the L90s + get preferred, but that don't make the L85s poor quality in their place either :)