The only problem that I had to face in GFWL is the XLive anti-cheat check that used to trace out debuggers/Trainers in no time.
CH have really done a wonderful job on making Trainers for GFWL, but still they would be a little restricted in functionality as compared to normal games.
Otherwise, it is a wonderful service to manage your games, play online, etc.
That summarized it pretty well...
I guess I'm special then..
On battlestations pacific the voice system never worked and alot of people were just broadcasting noise, screeching, static, etc etc
it also kicked people out at random sometimes, not saying any sort of error or anything (not sure this was due to GFWL)
Dawn of war 2 wouldn't even start for me, GFWL was complaining I didn't have a legit exe (which I did)
Gears of war had the same deal Dawn of war did.
I guess I'll give GFWL a chance, Red Faction looks like a really fun game, and the physics look really nice.
maybe urs is a special case but certainly not an isolated one. personally i've never faced a problem with GFWL games. maybe some restricted trainer and cheat functionality but otherwise a pretty good experience. CH has certainly done well to adapt their trainers for GFWL games. its all good.