There are charts showing the effectiveness of the Soviet NS-37, Vickers S, and the BK 3.7cm. From what I am seeing there is no clear advantage to any of the guns, only gun platforms.
The Stuka may have a tighter turn radius at stall speeds, but that hardly counts as "more maneuverable". The Hurricane IID will run circles around the Stuka. Check the stats. The Stuka might win in terms of pilot protection and sustained turn rates, but that is about it.
If people would just take the time to learn the Hurricane IID, the Il-2 would be left in the hanger far more than it is. I cant remember the last time I took one up. They only time I think I consider it is when I know there are multiple soft gv's inbound to a town and I will take up rocket for the near miss hits. Rockets are great for blowing tires, treads, turrets, etc.
I'm not so sure about that. The 40mm definately FEELS less effective against tanks, especially when firing at side and rear armor, instead of top armor. Now it may be just perception, but perception also plays a big part in what people fly. The 40mm is also less accurate than the 37mm, and has a slower ROF, which combined with the fact that the IID is just a less stable firing platform mean more time spent taking out each tank, regardless of the effectivness of the rounds themselves.
As to the manuverablity, I was actually refering to the responsivness of the aircraft. The Ju-87D-3 just feels quicker and more responsive to the controls (particularly in roll rate), than the IL-2 does.
And you also say 'if people would just take the time to learn the IID', which implys that the IID is inherently different in the effective method for engaging targets. The only possible culprit for that would be less effective armament, else attacks could be made in the same fashion as they are with the IL-2 without any loss of effectivness (relative to the IL-2), regardless of if they are the MOST effective, or even efficient, method FOR THE IID.
So no, its not 'if people would just learn the IID', its a matter of the IID having less effective
armament regardless of the effectiveness of the individual projectiles.