Why run dual quads?
Partially depends on the style of intake being used. In my case, I chose to run a tunnel ram, which gave a large performance boost over the single plane. Dyno tests have shown less than desirable results from running single carbs on tunnel rams, so dual carbs it is.
Due to the season, I did not get carbs absolutely dialed in to optimum performance. I can say with certainty, driveability, manners, and performance were all equal to, or improved over single setup. Mileage went from 17.4MPG imperial to 15.6, not nearly as bad as I expected. Again not fully dialed in. Drove it on an 800 mile trip with no issues.
Many people claim tunnel rams, or dual quads are not street friendly. I would suspect these are the same people who haven't done it. Oh, and I have no chokes either.