It does have a reputation as the troll unit to build once the game is already won. I think this is an unfair reputation in larger games where it's extremely powerful with appropriate positioning. What other unit has great AI, great AT (up to medium), great mobility (it's a race-car with vet), great armour, and moderate cost all in one package?
The weaknesses are:
-lack of turret (but it's fast and the jp4 also manages fine with no turret)
-facing heavies (axis generally doesn't have any AT issues in a combined army)
I hardly play now (internet) but mostly I went brummbar first every axis 4v4 since last year