I just got around to trying out the Multiplayer Campaign and have to say that I am really impressed by it. I started a coop campaign with my brother, where he played the Macedonians and I played Sparta. We nevere encountered synchronization issues. I had two crashes, but I also get them in Single Player, so they are probably not Multiplayer specific. I think they put a lot of very nice touches into the Multiplayer Campaign:

- You can paint Red Arrows, Blue Lines, and Green Lines with a T everywhere on the Campaign Map and the Battle Map. This is really nice if you want to coordinate movement on the map and want to show something during the battles, when you are spectacting. The fade after some time and work really well.
- You can spectate every battle your coop partner has. As an added bonus your coop partner can gift some of his units to your control. It's really fun to fight a combined battle where one of you runs around with the cavalry to outflank, while the other has control of the main battle line.

All in all I had a lot of fun with it and will continue further. The only downside right now is the performance. We both have PCs that are two to three years old and it shows! The loading time between turns is only as long as in Single Player but it drags on seemingly forever. Also during large battles on the campaign map the performance can get really bad due to the spectator thing. We did a combined assault on Athens, with one army each and everybody was moving in slow-motion.

We're still trying around with who hosts the campaign and whether this has any effect on the performance issues. Unfortunately we haven't figured out yet how you can swith hosts in the middle of the campaign.

All in all I really like the Multiplayer Campaign and think it's a wonderful feature!