Quick multiplayer review.
First off there are basically no servers up, I've seen 2 servers over the past 2 days, both yesterday. BUT more and more people are getting into the game and organising server times so this will obviously improve over time.
The net code seems to on the weaker side at the moment compared to LFS, it has terrible connection/disconnection lag when someone joins the game goes into slow-mo, then speeds up again to catch back up. If you're in a turn then your lap/race is over, don't think the disconnect lag is as bad but it's still there.
The over all lag level seem a tiny bit high, but that could be down the server, didn't really pay attention to the pings, was too excited to find a server.
There is no collision detection right now, the dev does say this on the forum in the intro to the game spiel. This is probably a good thing right now, don't think the net code/people skill levels are up to having col detect anyway
There also seem to be masses of tire smoke coming off other bikes under braking, could be setup but I think it might be something else.
The sounds of other bikes seem to be just as loud as your own bike so it can get a little confusing; other bikes just seem to be very loud full stop.
Those are the main online points I think. I my opinion it has been released a bit early, a couple more beta testing weeks would improve it no end. The forum could also do with being a tad more organised, but I don't think the devs thought it would catch on so fast.
But saying all that and like everyone is saying the game is very good and has so much potential it's unreal, hopefully things will move forward fast.