The best way I could describe the difference between Il-2 and AH is I have to think ahead more in Il-2. In AH, everything is light and precise; in Il-2 it takes longer to set up a kill. It's kinda like the inertia of WB (though not as bad) combined with the pre-1.3 AH flight model. It is a more challenging flight model in many ways, in particular in the fine movements. If you are into realism (read "challenging"), there are definitely more variables to consider in the Il-2 equation.