Technically is a hard counter. Another thing is that you could keep it alive from ZiS or T34s.
@FestiveLongJohns, sounds stupid, but bigger absurdities are written here.
I don't think that any top 500 player has any problem dealing with a pure AI unit only useful at close range. Only in urban maps like Ettelbruck Station Shocks could be difficult to deal with.
Shocks are amazing, but also have plenty of counters. Being a proper use of axis long range infantry one of them.
I think the OPs issue, despite the title, is more along the lines of the overall strength of the soviet faction from start to finish. Most factions have some sort of window of weakness that you can exploit, the soviets have insanely strong elite infantry and a number of extremely viable call in options.
IMO the main reason they are so strong is because they have the best call in heavies in the game. Their actual core army is pretty limited by the tech costs, but this isn't really unique to the Soviets. The Ostheer have the same issue, except their only real option in 1v1s is the Tiger. Against the USF there isn't really any reason to choose anything but the Stug E. It's always a better choice to forego tech'ing and save the fuel for more call ins. Without strong call-ins the Soviets would be pretty shit.