the problem is that it is way too accurate and hits like a truck everything. 1 accurate hit and squad is no longer fit for combat
Tbh it hits everything very accuratly. At least in 3v3\4v4 its a meta for a soviet to spam them. Imo it would have been some what alright if not the fact that it comes with 6 models, and to decrew it you need to kill all 6 of them.
With its raw damage, its impossible to counter it with your own mortar, not only because 120mm outranges and outdamage you, but because it can outsit you. This only allows it additional aggresive placement, making it even more accurate.
But over-all I would say that it performs somewhat on a resonable level, but it survivability should be tonned down drastically, to be 4\5 men and decrewing with 1 model left like other mortars. Considering you already have better range and damage, there is no reason for it to be almost immune to other inderect inits and hard to decrew.
This and the fact that almost all of the best soviet commanders comes with it.