I do think they work, I have my favourites as mentioned here, Jo Malone, expensive, but they're gorgeous and have staying power, unlike some of their perfumes. I thought Peony and Blush Suede was a nice winter one, sometimes it's not the initial scent but the lingering one after it's been activated for a while, that I like, if that makes any sense. I've tried so many, The White Company, St Eval, Neom amongst others. I have one in the downstairs loo by a brand called Inis, which everyone who pays a visit there remarks "that's nice". Of late I have also discovered one I really like from the National Trust shop. I'm a bit of a reed diffuser hopeless addict, if I see them in a shop, I'm over there like a shot.