Yeah, so you'd think. I've only just bought Arkham Asylum, and that's still annoyingly unstable. The only way I can get it to start is if I've freshly rebooted my computer, otherwise it crashes straight away on startup. And then I suffer in-game crashes that mean I have to restart my entire machine before I can then restart the game again. Sooooo annoying.
I can't actually believe how bad Games for Windows Live is... basically if I click on the GfWL overlay before a certain point in the intro/loading sequence, the game crashes. GfWL offers literally no benefit that I can perceive, other than making the game unstable. And I won't even get into how ridiculous it is to have two overlay systems (GfWL and the Steam overlay - which is at least useful).