[Big-Foot]

FWIW - I tend to stick with Holley. Their quality control is very high (I believe higher than BG is now) and their products are well supported by both them as well as the aftermarket.

With only one exception (in hundreds of car/carb combinations I have built, supported) have I ever had to re-work or adjust the air bleeds to the emulsion tubes. Just because it can be adjusted does not mean that it should be.
I can't tell you how many times I have had to re-baseline a carb because someone got in well over their heads trying to make their car faster or more responsive, when the problem was never in the carbureator to begine with.

A well tuned vacuum secondary Holley will outperform a double pumper on the street any day. The Vac secondary carb can be far more responsive than people give it credit for.

More air and More fuel does not a faster car make. You have to have the rest of the package (gears, cam, heads, exhaust, ignition) in balance or you are just slowing down rather than going faster.