Most of the time I don't really care about it, however there are times when I've abandoned playing games because of it.
Example - I recently decided to place Batman: AA again, after trying to login and having to wait several minutes for it to do so, I assumed that would be it. Oh how wrong I was.
I ended up having to download 5 updates, 5!, after every single one I had to close down the game, reopen it and log back into the GFWL. What is even worse is none of the updates seemed to be for the game itself, yet if I said I didn't want to update, I couldn't log in and therefore couldn't play the game with saves turned on. It ended up taking over half an hour between opening the game from steam and actually being able to play and that is just not on when have already spent a couple of hours downloaded 8.4Gb of game.
For the most part it's just another shoddy form of DRM which only serves to punish paying customers for buying a game new because develops don't seem to realise that pirates can, do and always will very easily get around all the toss they bolt on.
To summarise, as just a platform for people to share retard points with their dribbling console chums I couldn't care less, it doesn't hassle me much and I can deal with just logging in to it for the small amount of games that require it, however when it comes to it's constant updates and DRM, I would rather just not play those games.