Difficulty is very adjustable. You can even select not to be able to have an outside view.
In the other extreme you can have simplified flight models with a no cockpit view with a HUD-like display, planes marked with coloured text of type and distance next to them and unlimited ammunition, invinciblity, ...
Of course you can choose anything in between as well, even if you want to have your location and/or your waypoints marked on the inflight map.
In the most realistic mode it has a very steep learning curve: You'll have to manage your engines, and get used to each plane individually.
What I enjoy very much is that each plane has a very unique feel to it, very unlike in the CFS series where the planes just differ in turning ability and some other data, but all feel pretty similar. You can beat just about any plane with any other if you stick to the tactics and manoevres which are best for that plane.
The AI is a little unmatched. They perform much better at turn&burn and don't do much boom&zoom. So it is pretty good in most Russian planes, but sucks in the German ones (in IL2/FB), because they just don't perform well in t&b.
Shooting well takes some pratice, too, more than in most other sims at least, since you really have to hit the plane model, not just a box around it (unlike in e.g. FA)
_________________
|