Hello,
I do not use MacBookPro with retina display but MacBook Air (1.87 GHz, i7, 8GB ram, OSX 10.9.5, 1920 x 1200 @ 60 Hz) and yED is extremely slow: it hangs after EVERY step! I think it is OSX related issue. Are you going to do something about it? If nothing changes I am forced not to use it anymore as I do not have soooooo much time to waste. Thanks, Maggie