Always check off no to fixed host. If you're going to be racing people from all over the planet in a room, best to turn off voice, too. I race in a lotus room about every night where half the people typically are in Europe, one or two in south america and usually the rest is american and Canadian. We race with voice on. Only time we have brief hiccup is when someone is leaving the pits and that doesn't even happen often anymore. I think they've been working on the servers.
Either way, if anyone has a dodgy connection, it's going to screw the whole room. There is a member who is in the top two gt drivers I've ever seen personally and he often can't race with us, because his connection always blows. It sucks, because he is outstanding.
You really just have to have a whole room of decent connections now. Too much data being sent around from p2p, to PD, etc. It's actually pretty amazing when you think about it. Racing people across the world with more or less no delay in action or voice. I race with guy from Ireland and we were talking the other night...realised it is like talking on the phone to a neighbor. Zero voice delay. Just something I've never thought about. I know sixteen year olds expect this, but it is something else to me and I'm in my mid twenties lol.
We usually don't have connection issues. It's usually peoples' ps3 crashing when starting the race. Which means a manual grid start.