is aircraft worth it?

[Heimdallr]

I think, you could use aircraft for interdiction missions, too. Ideally bombers with tons of heavy bombs could slow down enemy advance when bombing main road along its direction.. crates on the road make the move slower. Of course, this could be done with arty as well, but not in such a nice row

Personally I don't often play against full AI(purchase, deploy) at least I make the purchase.

I agree, aircrafts are good for scenarios and for PBEM when respecting some purchasing rules.