Thanks for bumping this thread - I recently expanded the aircraft comparison, adding two more planes:

It'd be cool to have more game uses for cargo planes - for example, maybe delivering airfield supplies to a field could effect ENY for aircraft at that field only, allowing the use of P-51s and other ENY-lmited planes at a resupplied field even though they are unavailable everywhere else for your side.
Or, maybe a smattering of small fields across the map could start unowned ("neutral") and show in gray color on the clipboard map. It could take a few cargo trips to this field to activate it and "own" it for your side. Must deliver troops to man the field, airfield supplies to build up fuel and ammo stocks, etc. Then it becomes a fully activated field owned by your side.
Still pondering but I think expanding the roles and aircraft available to haul cargo might add more things to do in our sandbox, without taking away anything from other players.
I'd also like to see the effect of the M3-resupplying towns limited more. It just seems like this small little vehicle can deliver supplies that have an out-sized effect on the defense of the town. Now, a C-54 flying over the town and dropping 4 pallets of supplies would be a different story....and look very cool in films besides.
The C-54 could also be very effective at resupplying strats; carrying 4x the cargo tonnage of the C-47. Its the B-29 of transport aircraft...