Oh, the hours of hilarity that OFP used to produce back in the day, not to mention the more serious wargaming that was possible.
The huge islands really were the stars of the game and the group of guys I used to play with (~20-30 guys, all with mics and - thankfully - almost all 30+ and ex-military) would have training missions lasting several hours at once, meaning lots of terrain to cross on foot while trying not to be spotted. The missions were always exceedingly difficult with the odds stacked against those on the "good" side, so we didn't always win, but it didn't matter. Some of the most fun I've had online, ever, and playing with (mostly) ex-soldiers really helped to authenticate the experience.
That being said, we had a LOT of connection issues when trying to get some games going. One or two people would often drop right when the map loaded, meaning we all had to go back to the lobby and try again. I remember wasting 45mins+ almost every time we played because it was such a pain getting everything set-up and running smoothly with connections coming from all across North America.
Anyhow, here's hoping for at least a partial-revival of the same goodness and a step up with the netcode.