OK..now I have got it downloaded, here's what I thought:

Installation.
Neat and tidy. It did everything simply with no problems for me. It does take a while to install, but everything went OK with no fiddling about needed. I did install a no-cd which presents no problems to those wanting to do so.

Flying.
Flew a few quick missions, and frame rates seem to be OK on the default settings. Flight models seem quite 'heavy' at slow speed, which felt natural. Higher speeds yield better responses. Planes had a definite feel to them. The Dr1 turned well, the Se5 was more of a straight liner. SPAD 13 was slow on the turn, but a good vertical fighter. Exactly as you would expect. The only thing I don't like is the stall characteristics. Not a reflection on OFF....it is just like CFS3, and clearly a problem with the engine. It's bearable, but annoying in so far as it highlights how little effort the original game put into slow speed stalling.

Graphics.
It's pretty. With plenty of PC power, it looks very pretty. Terrain is a LOT better than CFS3 stock ever was, and that is just as well. You can still fly through the trees....but agian...that's not OFF's fault! Buildings and airfields look really nice and period. Turn off all the CFS3 helpers and it looks nice. Dr1 could use a central iron sight for it's twin guns! Nice to see no ammo counters etc. cluttering up the immersion! Flame effects look nice, but I do wish the planes hitting the deck left more visible debris....but again...it's exactly as it was in CFS3.

Other bits.
Hangar views and pilot management setup is really neat. It's a bit more involved than the original game, and streets ahead of what I was expecting!

Overall....

IT flies nicely enough, within the limitations of the original game engine. Graphics are neat and accurate, and the overall feel is nice. Well worth the download, and MILES ahead of the commercial WW1 add-on for CFS2. I think this will be getting better as it grows to cover more planes, and I look forward to a few heavy bombers creeping in as flyable

If you like WW1 and own CFS3, you would be daft not to try it