I completely agree, leaving slack in cords is highly recommended. Tight cords can start to fray and have problems at connection over time. Also depending on how you wind, the cord may lean and kink a certain direction if pulled tight. Anyone who uses a power head canister, in particular older style without the cord built into the wands needs to leave slack in the bottom, or else someday down the road, you'll find yourself with wirecutters and electrical time, splicing and repair frayed or broken wires.