Well, both, really.
My sack numbers are very low most games and I play on All-American with everything at the base 50/50 except I turned down CPU's Interceptions a bit. I found a slider set that basically uses Auto-Subs and Penalties instead of changing Gameplay Slider values and it works really well except for the fact that I average maybe 1.0 sack per game, if I'm lucky.
This is strong advice and what I was hoping to hear.