What size hose works best on a retractable reel?

Reviewers on r/HomeImprovement note that 1/2-inch hoses on retractables can deliver noticeably weaker flow than the 5/8-inch hoses most outdoor spigots are sized for. If water pressure matters for your use (pressure washing, sprinklers, long runs), opt for a 5/8-inch model even though it costs more.