My biggest problem is the occasional message saying "you have been kicked by other players", without anyone even voting. It then puts you through the long load time from online to single player. You then have to go back into online for another long load time. Why couldnt it just put me in a new server instead of single player?
Another issue for me is how often my phone goes off. It was annoying enough in GTA IV, now its even worse in GTA Online. I would be doing something such as being attacked by another player or driving fast through the streets and the phone will pop up. If the phone comes up and i am sprinting or needing to press handbrake, it will answer the phone and completely fuck me up.