I've played a ton of matches against Quan Chi. I feel that if he goes Summoner, you ABSOLUTELY must go Cutthroat, since he outzones the fuck out of you in Cybernetic. If you don't go Cutthroat you have no way to open him up at all, especially in Cybernetic. Essentially the gameplan is get to the corner and 50/50 the fuck out of him, since his wakeups are ass. Also something I've been doing, instead of going into a full combo, is mixing b12~db1, b31~db1 and forward throw, it's sorta like a vortex I guess.
However, if he goes Warlock or Sorcerer I feel that Cybernetic is best.