You said "after all one’s got a jetpack and the other a bionic arm, so we’re hardly talking reality warping power levels here."
You must have forgotten that the Winter Soldier has also had the same super soldier serum that Steve Rogers had. They went toe to toe in CA:TWS. And he jumped from an overpass with no broken legs.... etc etc
If he simply had a bionic arm, Steve would have destroyed him.
So enhanced strength and durability etc etc... Seems pretty super to me!
Just wanted to add that although we all know why they gave the Falcon Cap's shield, giving it to someone who in all reality, could only throw it about 20 yards, is not going to make very good TV.
His best mate Bucky should have been handed the mantle of CA imo.