I have a bit of a GFWL horror story. I was trying to play Bulletstorm. One attempt, I told GFWL to not install, as I can with Steam's installer thingy. I can cancel its access to my computer and it'll just not work. Well, I couldn't even get past the title screen. In fact (more of the game's fault) there was no quit button on the title screen. What do I have to do? I have to crash the entire game in order to exit it.
What's worse, though, is I finally let it install. Over the course of 45 minutes, I have to try to set up my account with a significantly reduced frame rate thanks to the overlay. Granted my computer was awful then anyway, but the game thought my computer was good enough for high settings and I couldn't change the options without a GFWL account connected online. So, with all the account set up going on, I got bizarre error messages. Among them, was a "Your account is corrupt, please delete it and try again." How does that even make sense. Well, I got mad, but I didn't delete it. I just logged in a few more times and it eventually worked. I played two chapters of Bulletstorm, oddly appropriate catharsis given what just happened...
And then I never played it again, because GFWL has been upped from "I heard this was bad" to the "Deal breaker" level of my scale of the things-to-tolerate list. I'm impressed it rocketed from a 4/10 to a 10/10... but that does mean I don't get to play Dawn of War, outside of Retribution. Darn.