If you're so great, why are all of your posts about how you can't shoot things down?

Have you set up your convergences and ammo loadings? Do you actually use a bit of patience and wait until you can get a good shot? I rarely get less than 10% hit rate in this sim and I am not very good. I can usually take down at least two AI aircraft a sortie.
Anyway, one visible problem with the AI other than the aforementioned crazy roll rates and ridiculous climbing ability (just like 1946) if you look at them in an external view it seems they have absolutely no control surface inertia. Their control surfaces can just snap from one position to another instantly. That certainly doesn't help.
Then there's the *utter* stupidity. Try loading one of the online dogfight missions on a map that has lots of hills. Odds are, the VAST majority of the AI aircraft in the mission will crash into a hill without even attempting to evade them. In one of the online missions where there are some very steep hills my flight was the only one that didn't crash uncomplainingly into terrain, and that was simply because I took control and climbed out of the way before they did so.