It's a standard Sherman with that toggles between standard rounds and HVAP instead of standard rounds and HE.
I use it all the time when I play Soviet. It fits amazingly into their T4.
In USF it's has stronger competition from the Bulldozer 75, but it's still an excellent unit.
The 76 is better for soviets than USF, it's like the Ostheer P4J.
The HVAP still seems a little pointless though, easier to just flank them with higher ROF regular rounds.
The 105 costs 140 fuel and does less than the m4a3 at 110 fuel. It seems pretty pointless to buy 80% of the time unless you already have a bunch of m10s or jacksons. Its a little more durable and effective vs infantry but its a niche pick not a standard one. It's only 70 fuel less than heavy tanks which do everything better and are more flexible
Even if its interesting it's not very good.