I don't know much about OFP but I did just buy a copy of OFP Gold with Red Hammer over at SimHQ "Buy/Sell/Trade" forum ($5.00, couldn't beat it). A very odd thing happened to me after I installed it to get the feel for it. I'll usually tinker around for a long time whether a game's very good or not...but after about an hour or two I actually uninstalled it and shelved it. Maybe after newer games like America's Army, BF 1942, and RTCW I just expected more, but I didn't care for OFP at all.
Don't think this is any kind of flame because I know many people enjoy OFP. I just don't see what all the hype is about (just my opinion). Of course I suppose if I were to spend more time and get some of the add on stuff it might be better, but I think I'll just stick to AAO for good teamwork and BF42 for good clean blow up stuff arcade fun. :)