I took my 2012 rMBP into the Apple Store today. It had been having the problem where everything would freeze except for the mouse pointer, and then the machine would restart (in addition to the occasional graphics distortion in Finder and Safari that I'm pretty sure everyone sees occasionally). This would happen about once a week on average and only started happening to me with Yosemite.
Luckily, I got a great "genius" who clearly knew what he was talking about and seemed to be pretty senior among the other geniuses. I explained the problem and showed him the kernel panic logs showing a GPU hang/restart. He ran the VST3 on my machine as the other poster described above, and it passed. It seems that Apple's procedure dictates that if it passes this test, it is not eligible for the repair program. The genius also said that Apple is telling the stores to send the machines to a central repair center instead of doing it in-house if they fail the VST.
However, the genius said he was going to send it in anyways, and if they refused to repair it and sent it back, then he would just order the part and do the repair at the store. He seemed to know that this is a long-standing issue with these machines and acknowledged that the kernel panic logs show that the GPU is regularly causing the machine to restart and that there is clearly an issue, even though it passed the VST.
Overall the experience went quite well - I was expecting to face much more resistance with attempting to persuade them that there was a problem with the machine. Based on past Apple repair experiences, I knew that there would be some sort of 'test' that the machine would go through, and if it passed whatever this arbitrary test was, then clearly there wasn't a problem with the machine and you are SOL. I was very lucky to get a genius who knew this was BS. They even replaced my MacBook power adapter which had some serious fraying/strain on the MagSafe end just from normal use. So, serious praise for Apple for the excellent customer service (or at least for this specific genius at this specific Apple Store). Faith in Apple restored.
It seems like if you have this problem and your machine doesn't fail the VST, then technically Apple will consider it ineligible for repair. So hope you get a genius who is knowledgeable who you can show the GPU Restart logs to. You can access these by opening Console and browsing to /Library/Logs/CrashReporter (I think - can't remember exactly since I no longer have my machine on hand). If the genius isn't buying it, then you will be forced to pay for the logic board replacement (similar to the poster above, the work order that I got emailed quoted $310 for the repair). I would like to point out, though, that there are several people in this thread who have already gotten a logic board replacement and said that they are still experiencing hangs and restarts (which would imply that it is at least partially a software issue). So, if Apple won't cover it, you may want to wait to see if Apple comes out with a software fix to help alleviate the problem before you decide to spend money on the repair.
I'll update on whether the logic board replacement fixes the problem when I get it back (I was told 10-14 days for the repair). Good luck!
