From my experience I just paid £650 to have my nMP repaired at an Apple store.
I have the standard D300 spec nMP. It exhibited all the symptoms of the recall on the D500 and D700 cards. It progressively got worse until it wouldn't start up. Lights appeared around the usb and thunderbolt ports but it wouldn't start up when pressing the power button.
They changed the power supply and the interconnect board and graphic card B.
I will test it out tomorrow and see if I get any GPU restarts
Sorry to hear you had to pay. I got mine fixed for free and it's nearly 3 years old. I made it quite clear I didn't think this was acceptable for a £2500 computer, and that I knew about the recall, and that I may have to ditch the platform etc etc. The Genius went backstage and a manager authorised free repair, providing there was no water damage.