Seems they can't handle divebombing very well - with the Stuka I had no problems, lining up with the target at angels 2, sweep down, release the bomb(s) and head home again on low alt.
Can't wait for the Pe-2.
With the IL-2 it's another story: Flying low keeps you safe from the big AAA - unless you're in range of the 20mm. :/ Soon after you'll look like swiss cheese, even if you're doing evasive actions. :/
I tried it like in IL-2 1946: An attack doing a circle towards the target. Didn't worked well for the 20mm, but works with the bigger ones.
Best way will be flying in pairs, where one's going to distract the AAA as a bait, while the other finishes them of.