I found the SAu-40 to be rather medicore rather than all-out bad. It's top gun is relatively decent and it's one of those tanks that can have it's moments of awesome, but gets sucked into matches that it really has no business being in. It defiantly not a Hetzer though.
Also:
Researched:
S-35 CA researched.
Undistributed experience spent: 12550.
Free Experience spent: 0