I also purchased the premium and just quickly tested the early access. BoF seems very promising indeed. Looks wonderful and I got easily 60FPS capped with my 6060x1080 Nvidia Surround all ingame settings maxed out using RoF profile. Under the hood there is definitely RoF engine which is purely a good thing: Flight model is simply fabulous! Engine sounds are also improved a lot compared to earlier IL-2s.
Only strange things I noticed was that early access aircraft seemed terribly difficult to control on ground. It felt like differential brakes weren't working at all. Also it seemed that my elevator trim didn't work although it was too mapped on controls. Clickable cockpit would be nice, but pretty much everything needed can be easily mapped, so it is really not necessary. Still, we are on very early stage with the sim and many things will change for better. I can't wait to fly the finished product and a campaign with He 111.
Next year or so seems nice for WW2 buffs. We get this and also DCS WW2, which will be another high quality product. Not bad at all, not bad...