I do like them as they are and never had the feeling they were underperforming.
they are a serious threat to infantry without the upgrade considering the exeptional cheap cost of 80 manpower.
with the upgrade they can battle the feared t70, katyushas, and any other sovjet trucks.
on top of that they can damage tanks on rear armor.
the skf 221 /2 is the one vehicle i build every game (mostly 2 or even more).
it is the one vehicle that often leads my statistic in damage ration after a game.
it is the veclicle that i get to vet 3 the most.
i cant see anything beeing wrong with it.
good luck using AC fighting T70