Well... I used this, got my code,pre-loaded and now nothing... By all accounts the game should have been available to me about 2.5 hours ago and still nothing. Obviously not OPs fault, but GMG seems to have severely dropped the ball.
Because you don't have to trust all of them or none of them. GFWL was always shit. Steam is pretty much agreed on as being much less shit. As for wanting to give your grandchildren your old games... I guess that depends on the person. I doubt I'll care about most of these games in 50 years.
Not sure if the 955 has the stupid Cool 'n Quiet feature but you might wanna dig around in your bios and see if it's there first of all and turn it off if it is. I was having weirdness with my computer and that fixed it.