Yes, I think the latest instalment of OFF really has taken WW1 aviation to it's zenith, and as Bullethead has said, it has almost become an RPG (certainly in Campaign mode)
Whilst I like QC, I find myself playing it less and less, as I get more immersed in Campaign.
I am not famous for my patience, and the likes of IL2 /CFS and others, never kept my interest in their campaigns for long....I generally just popped in and out when I fancied shooting at something...but OFF has slowly wrapped itself around me, and is a comfortable mix of historical accuracy, excitement and fun (rather like a good book, that makes itself difficult to put down, as you have no real knowledge of what will happen next!)
The other thing about 'games' per se, is that there is a start, middle and end!...once you have played them all the way through, that's about it!
OFF is wonderful, as there is really...only a start!...it never really ends....it just keeps on rolling along!
One thing is for sure though....other WW1 sims may come and go, but what Doom was for PC's and Manic Miner was for the Spectrum..OFF (imho) will be talked about by it's fans for years to come, as the WW1 flying simulator
A real legacy for it's developers and Aces!