Eddy 650 AVS vs. Holley 650 DP

Both can be highly tuned, The Holley can be adjusted more and in wider ranges. For all out performance you will almost in all cases see a Holley.

I believe a lot of people are more experienced in tuning one over the other so their choice is naturally going to be the one they are more familiar and comfortable with.

To me, for general use - flip a coin ... I use the factory AFB on mine, as it is a resto, I also have plenty of them around here so parts, metering rods and jets are at hand.