Rian, myself, Rian's sister, and Ubiquitous recently decided to LAN our way through the FS2 campaign. To our surprise, it worked quite smoothly, even though we were using two Tiger Macs, one Leopard Mac, and a Vista laptop. I was really impressed with the work the SCP crew has done.
We did encounter a few bugs. Firstoff, we couldn't play the cooperative campaign; it simply crashed when people attempted to join. We used the coop single-player missions instead, breaking out to VLC for cutscenes. I wish we could've just used the coop campaign -- any tips?
Second, the Leopard computer kept freezing every time we left a debriefing, and, oddly, if we spent too long in a briefing. It was quite arbitrary and puzzling!
These bugs are really minor, though, and although we did suffer a few mid-mission crashes (couldn't get through Argonautica without all the clients disconnecting, and clients randomly exited or jumped out during Into the Lion's Den), it was a joy. We all commented on how surprised we were that it worked even across such disparate OS and hardware profiles.
Three of us were using the MediaVPs, one wasn't. Don't know if that would affect anything.
Overall, a lot of fun. The campaign missions are really improved by human partners, and Bearbaiting has never gone so smoothly.