The reason I went with this set up is because it's a state-of-the-art carb, and being a 4-bbl it's essentially a 195 CFM with 195 in reserve without the inherent complexities of running multiple carbs.
Furthermore Holley has this aftermarket stuff down to a science and their customer support is outstanding. The carb comes with a DVD that goes into detail on every aspect of the carb including a simple process for determining the correct jets. Parts are reasonably prices and readily available as is phone support if you need it.
I can't speak for everyone but having a piece of 21st Century technology at this critical point in the powertrain seemed like a smart move to me.
