Not much really new here, I just wanted to add my tiny voice in praise of what I believe will be the standard other WWI sims will try to match for many years, as was Red Baron.
The graphics, both 3D and 2D, are superb. The ability of the hardware to process more informaton has made it possible to add variety and details that couldn't be done before. I personally am especially pleased with the terrain rendering. Identical tiles repeating over and over again in an identical pattern have been replaced by unique identifiable landmarks that can be used for vfr navigation just as real pilots do to this day, reducing or eliminating the need for using a gps-style map that is (game-wise) decades in the future. But that can be said about so many flight sims these days.
The one thing that Red Baron
always over other flight sims of any era was its campaign. RB's engine was a marvel, creating dozens of flights some of which could intersect yours and others which came nowhere near. You could fly your entire mission without seeing a single aircraft besides the ones in your flight, which may make for a boring flight, but it is the way it was for the real pilots. OTOH, you can leave you intended flight path and run into several flights of friendly and/or enemy aircraft. You just never knew what you would find where, again just like it really happened. No other sim I've tried came close to the "What will happen when the wheels clear the ground?" feeling that must have run through the mind of every pilot from the newest replacement to the von Richtofen's, Ball's and Guynemer's. Until now! OFF's campaign engine does
exactly what Red Baron's did, create dozens of missions for dozens of squadrons on both sides and lets fate and your choices decide what you see and what you don't. You could just miss bumping into a half dozen nice, fat, ripe BE2's only to find yourself mixing it up with the whole of RAF 56 or Les Cignones. Now
that's 'as real as it gets'.
I have to say that the online experience is not as good. As a regular in Vasco's Sunday gatherings I can say that the interface is cumbersome at best (no metaservers means all games must be played on the host's ip, therefore if he has a problem everybody is toast). There is also a 'stuttering' problem that must be in the game because too many people see it for it to be a connection thing. OTOH, the fact that AI aircraft are available in multiplayer makes for more possibilities than one had/has in Red Baron.
And while we're on the subject of AI, if you're used to the AI in most other sims, hold onto your hat. In most games, they fly in predictable patterns and make the same moves over and over again. While I still rate human pilots better,
these guys are tough. In Red Baron, IL-2, MiG Alley and the CFS series it was next to nothing to take on three and four enemies at a time, even on 'ace' settings. I'm a lot less reckless in OFF. They even seem to know when you're gaining an advantage over one of their comrades and will come to his rescue (although I've not had the same luck with my wingmen

).
Throw in full support for Track IR and overall it's what every simmer (at least the WWI crowd) would expect from Red Baron 4 or maybe even 5.