GFWL is not behaving properly - it is still very much a piece of shit and is my biggest complaint. I have trouble summoning people because of it and getting it up and running (I run a local account for GTA4 so it was a pain to do account switching for online) was annoying as hell.
Besides that - port works great for me on my ps3 controller. The graphics are so sharp now, I own it on PS3 as well and I could not even play it on that console because it is so blurry.
Also GFWL client refuses to quit sometimes - have to kill the process after the game shuts down, and it keeps seperate resident processes in memory (WLIDSVC and its counterpart) at all times to stay "online". Nobody should be defending this shit.