Edelbrock/Carter 800 AFB Or AVS?

I don't have direct experience, but from literally everything I've read and heard people talk about @GTX JOHN is dead on the money. The AVS is easier to tune, primarily because the secondary air door is above the boosters and like a Thermoquad the tension is readily adjustable. Being above the boosters also supposedly makes the transition a lot smoother and that normally results in lower ETs.