I wouldn't really say the lefh is all that bad stat wise. It's just that neither US or USSR really have any defensive builds really to make use against. So there really isn't a reason to ever build it. But imagine if it could hurt IS-2s and ISUs. I think it might actually get some use.
From my experience LeFH has some issues, the biggest is of course accuracy which is a nightmare. There was more shells that hit outside the targeting circle than number of stars in the sky. It's reload time is horrid, and number of shells fired is quite small. This is of course a consequence of previous game states, when LeFH was shooting all the time, and is the smallest issue.
There is also a role for LeFH, which I experienced in one of my 4v4 achievement-fests. Both ML20 and LeFH vet very fast, so when a soviet goes heavy T2, the counterbarrage is quite useful indeed
There is still ingame text describing LeFH. Something about it being not as destructive as Soviet arty, but having a good rate of fire. What a shame it won't return to that state