Are down-alternative comforters good for hot sleepers?

It depends heavily on the fill and shell. Across the reviewers we read, lightweight polyester fills with breathable cotton or bamboo-viscose shells regulate temperature best, while denser 'cozy' fills can trap heat. Notably, even some comforters marketed as 'cooling' draw complaints in r/Bedding from sleepers who still wake up warm, so prioritize lightweight all-season weights and bamboo or cotton shells if overheating is your main concern.