I would take it the other way around if you ask me.
Increase Pen, decrease rate of fire.
Better performance against heavies, even at Vet0, worse against mediums and Pumas
This, actually. Usf has plenty of good high DPS low pen AT options (zooks, M1), so jackson could be the heavy counter.
The only issue with that is the fact that they'd get dumpstered by panthers for lack of enough DPS since the panther is almost as fast.