I havent read the articles in a while. Sometimes I re-read the links...lol. But, what you needd to realize is this. More air and more fuel make more power in every engine. But, the primary way that mix is fed, is it's drawn in.(in NA stuff anyway) So you can only get so much "suck". More rpms, longer stroke cranks, bigger bores, smaller ports, dual plane intakes, all tend to increase "suck". Something else, most new holley drivitive carbs (and some Holleys themselves) are not rated the same way as Edelbrocks and older Holleys. Generally, the old way is to dry flow them. That is, they measure air flow thru the carb at WOT with a given level of "suck". Newer designs are wet flowed. That means, a liquid that simulates fuel is run in the carb during that same airflow test. But because the fluid displaces some air as the carb mixes it, the total cfm drawn thru is smaller on the newer test. So, you dry tested 600cfm carb really flows a max of about 580cfm wet. But that Demon, will flow the advertised rating of 750 wet. Dry flowed, that Demon will flow closer to 820cfm. Comparing apples to apples, it a much larger carb. What that means is, your engine has a given amount of "suck". The hole that the air/fuel enters thru is fixed. In your case, its smaller. The bigger hole will allow more mix thru, but the bigger area will lessen the "suck". So more rpm will be required to get that loss back. Nevermind the things like air bleed size and stuff that's calibrated for a larger engine. Numbers dont lie. but lagazine articals NEVER show everything. That larger carb will lose some low end to give it more higher. A dyno shows a better number. But you dont drive or race dynos. It's simply a tool, that says rev it, the bigger carb makes more at peak. In your car, it will lose fuel milage, lose response at low throttle and off idle, and then pull well if you keep it at fullthrottle in the higher ranges more. most stree cars dont live at full throttle much. Dynos do. Stick with the smaller carb, and read the articles with mroe of an eye that you might use when a vaccum salesman comes to your door. Really 80% of any magazine's content is strictly for advertising revenue. I'd love to see a magazine that never tells you the brands of the products. Then you'd just be interpreting data, not brands.
