Well after finally getting everything installed.... I like it. I really like it. Yes there are a few foibles and graphical issues and my FPS is only at 20 over towns and cities but who cares? The trees are full and rounded (and collidable. Oops), there are some birds (more needed please), the buildings look miles better, the whole thing - it just looks much more realistic.
I did what I set out to do and that was fly my Spit from France to England at dusk with a beer and I was very, very happy. I've yet to test the different settings so maybe I'll make it better still.
Cheers ED, have one on me.