Some of the things I saw:
1. Changing my faction was not always permanent. Sometimes it would flip back to Terran. In particular, one time I had changed to a custom civ, then I did a chat, and as soon as I chatted it reverted my civ back to Terran.
2. Players would occassionaly dissapear from view of one or more of the other players. This happened to me several times after I clicked ready, Seilore said he couldt see me anymore so I left the lobby and re-entered (assumption was if he cant see me than likely will be an issue starting the game). This happened to the other 2 players also.
3. Players got randomly knocked out. I was knocked out a couple of times immediatly after a chat.
4. Chat room box doesnt scroll (no scroll bar) and changes color, often new text just will not scroll up at all. Also formats irregularly, sometimes only one word on a line of text.
5. The ready box doesnt really work the way I expect - it doesnt seem to toggle back to an unready status. Once I am ready, it seems I am ready and there is no going back (which it really needs given how unstable the civ selection process is)
I was able to get a 2 player game going with Seilore before, although after I think about 20 turns, we crashed, and every attempt to restart led to a crash at the same turn.
These are all MP issues, in SP the game feels pretty solid to me. I have over 300 hours and the crash rate in SP is acceptable, and has always been recoverable, unlike the MP game with Seilore.