I sold my 2011 MBP for the same reason. Never had any problem with it. But due to rumors that some 2011 MBP had faulty graphics, even though I had no symptoms, I sold it.
The specification is listed on my signature.
I couldn't afford to pay 700 dollars out of warranty repairs.
Though they do still fail the 6490 model 15 hasn't failed as much, as the lower clocked gpu and similarly less powerful Sandy bridge cpu do not generate as much heat as the higher spec MBP models.