The problem with Holleys is that they're not tuned out of the box for a daily driver, whereas the Edelbrock is. The Q-jet/Thermoquad design is just overall much better suited to daily driving - smaller primaries, vacc. secondaries, etc. It's not that Holleys can't be made to work - mine works great - but unless you get a tune or have an Innovate meter and time to fart around with it the Edelbrock is always going to give better milage and overall responsiveness. All IMHO, of course
I would note that if you have a vacc. secondary Holley that's appropriately sized, then you CAN get there with an Innovate meter or a dyno tune. For a mild 350, a 600 or 650 CFM is fine - although typically what I see is a 750 or even an 850 double-pumper.
Now that my kid is using my truck for a daily driver, I'm pulling off my LT-1 3310 780 CFM vacc. secondary carb and putting on a 600...and I have to go through the tuning process all over again :/