I have bought it, played it and kind of enjoyed it. I was dissappointed with the paucity of airframes – you have to buy more (the standard offering is the DVIII, Albatross DV, SPAD and Nieuport 28 IIRC). I did buy the SE5a and I have been shot down more times than I can count.
It’s incredibly difficult and I turned much of the realism off to avoid losing interest and there wasn’t much activity on the multiplayer side of things. Graphics are lovely and it does have a nice feel. Did I mention that it’s difficult?
If you have the time and patience then it’s worth the money – a Logitech driving force steering and Race Driver Grid has my attention at the moment, closely follow by Modern Warfare 2 so RoF is gathering dust at the back of my hard drive for the time being. I will go back to it though!