This:

Quote Originally Posted by 'Niley',index.php?page=Thread&postID=167235#post16 7235
20-45 Scarlet, at 40ish it was getting slow but meh.
45-60 Strat, they were getting 1800ish exp per kill.
Don't mess with SM graveyard, library, or armory. Just single pull Cath every time and your guys will fly through levels 20-40.