Edelbrock Performer vs Edelbrock RPM Airgap

What about cam timing or, carb? Was cam degreed? Lot of variables that can make an engine sluggish. I had a 1406 600 eddy on a 340 w an iron 340 intake manifold and a .444 cam car always had a slight hesitation. I swapped to a 650 holley double bumper and the difference in throttle response was unbelievable. Of course timing and everything else should be checked 1st. Maybe just me, but I have have tried a few edelbrock carbs and none of them had a crisp throttle response.