What CFM and MPH do I actually need?

Reviewers consistently point out that CFM (air volume) matters more than MPH (air speed) for moving leaf piles. Homeowner-grade backpacks in the 600-800 CFM range handle typical suburban lots; 900-1100 CFM commercial units are reserved for crews, acreage, and stubborn wet debris. Handhelds in the 400-500 CFM range are fine for hardscape and small lawns.