Its tank holds just two gallons, and the small filter needs to be cleaned frequently, but this ultra-portable, toolbox-size model devoured all but filter-choking drywall dust with great efficiency. Its 28V lithium-ion battery lasted well over 30 minutes and provided easy, cord-free operation – but it's sold separately, for about $129, along with a $59 charger. These extras means you'll spend about $300 for everything. [$100, vac; $129, battery; $59, charger;]