GFWL is terrible, as simple as that. I have always had problems with this system and multi-player is the least of them.
My latest problem with this disgusting system was my account being hacked. I logged in to my account and noticed that I have received FIFA achievements while playing Xbox360! Moreover, I have bought some in-game items within FIFA, up to the point of spending all my money!!! Now guess what, I don't have an X360 and I have never played FIFA and I have never bought any in-game items in FIFA.
When I Googled for a similar problem, I noticed this is a very famous hack which has happened for a huge number of Live users (including but not limited to GFWL users). The hackers used FIFA to buy ingame items and steal money. Many people have been affected by this hack, but Microsoft simply claims that their's nothing wrong with their security and this was the users' fault! They say we (the people who were hacked) gave away our passwords on forums! Now after having used computers for 25 years, I know how to protect my password and I know when a company is trying to be clever by putting the blame on me.
GFWL is terrible, even by lowest of the standards.