On friday (and the early ours on saterday) we were with two / three players: Bas (Mac OS; host) and Quis (linux); and we tried to get Wassasin (linux) in with portforwarding over the internet. I don't know which dumps are from the two players and which are from the three player game.
On sunday we were with five: (bas (Mac OS; sometimes host), Quis (linux; sometimes host), Edea (windows), awesterb (Mac OS) and Wassasin (linux)) and had quite a lot of desyncs. We noticed a lot of them kicked out both of our Mac OS players, but sometimes just one person, or two (probably not so) random ones. The game got into a lot of desynchronization loops, but that might be because after a desync which kicks out two players, they reconnect at once probably hitting the problems with connecting at the same time.
Most of the loops we needed to fix by loading an older autosave, sometimes it happened again, and sometimes it didn't.
We have no idea what we were doing in most of the desyncs, so I don't know whether you can do anything with this, but I present to you: 4GB of desync logs
http://struik.quis.cx/~quis/factorio-desyncs-0.11.1
(However we only player for about 6 hours (two in the first game, four in the second) we had a great day, even with all the desyncs. Great game devs, great game!
).