There are loads of a/c that should be added, im all for He-111 for example. What comes to soviet bombers, we have the most important one (which actually is a ground attack a/c). The soviets didn't lay heavily on strategic bombers so no idea adding one. B-17F played a major part in the war so that is one major reason to add it, also,like I pointed out earlier it shouldn't be too hard to modify from the current B-17, hell, if we have 4 different versions of Bf 109G (which is fine, got to say this before I get all the Luftwaffles blowing on my neck
) why can't we have 2 different B-17s is beyond me?
And yes it is probably unrealistic to wait for the F version now that the B-29 was added. Personally I'd have preferred the B-17F (which historically was much more important) before the B-29 but I guess HTC wanted to provide some über candy for people to play with and perhaps attract some new customers.
The major personal reason for me blowing on the B-17F trumpet is that we could have 8th AAF vs LW scenarios spanning from early 1943, without the B-17F this is impossible.