I would say No Proxy definately. In beta the EU proxy was causing constant disconnects for me and a few others. The game has run near perfect with No Proxy. I don't know whether it's got any better since headstart but i don't see the point in going back when No proxy works fine :p
I need to use the proxy otherwise the game is unplayable. The only problem is, with the proxy, I have a 50% change of getting dc'd and it takes ages to get a successful login. RAGE
I have precisely the same issue. Without the proxy I can connect with little to no issue, but the lag in game makes it completely unplayable. It takes over 55 seconds for a response to occur if I don't get disconnected. Interacting with NPC's or even chatting is nigh impossible.
If I use the EU Proxy I get disconnected every few minutes, but I have relatively no lag.
This isn't a new problem, and it should have been addressed and resolved ages ago, there is little to no comment about the issue or expected resolutions from an official standpoint. So it's either use no proxy and don't play, or use a proxy and get kicked every few minutes and never complete a mission.