You know what's better then a ML-20? 2 ML-20's!
Seriously, a hit from the 152mm does immense damage, and with 8 rounds you are bound to hit something.
I use Terror commander to push with fast t34 and kv-8, covered by Ml-20's. Conscripts to cap and AT nade, and agressive enemies can be pushed off with the propaganda thingy. Tigers can be rammed by T34, followed by IL2 bombing run/Ml-20 shelling.
Last week I had a 2 vs 2 where my ML-20's racked up 100+ kills together. At vet3, there is always one busy bombarding.
Someone famous said "Artillery is the Queen of the battlefield". In vCOH, I was a happy arty user, in COH2 it is harder to make it effective, but finally I have found a way