As much as I love my clicky cockpits for some hardcore simulation, I loved the approach that IL-2 took. It is a great balance of realism, and the ability of the devs to develop more planes for a certain scenario and have way more richer battlefield than we have in DCS for instance.
There a couple of point where I think they really should improve compared to IL-2, which is the engine modelling (please, no timers), and some parts of the damage modelling such as hydraulics. Also I could add gunnery must be improved, IL-2 is really flat in that regards with both sound and bullet drops and simulation having room for improvement.
But when it comes to cockpit simulation, IL-2 is a happy medium for me.