I had a great experience with Apple Xchange. No fuss, great deal (got the $10 for $20 Yelp deal on top of it), impeccable results.
So I had spilled coffee on the trackpad of my Macbook Pro about a year ago, and the computer continued to work, albeit more slowly, until one day it just stopped working. I freaked out and thought it was dead. Saw the Yelp reviews and called Apple Xchange. Alan was able to tell me over the phone that my computer likely wasn't suffering from water damage but from hard drive failure. Sure enough, when I brought it in for him to diagnose (for free), he confirmed it was the hard drive and quoted me the same price he had quoted over the phone--$149 before taxes to replace the hard drive and transfer the files over.
I had brought the laptop in a couple hours before closing, and he had completed the job and called me to come pick it up by the next day. I am ecstatic to have my baby back, with all the files and apps intact and running faster than ever. Thank you so much, Alan & co!