i still use the cheap ones, but you have to know how they read before using them. i put them into a jar with a boveda 62 and then see where they're at a day later. then i mark them so i know what to add or subtract to have an accurate reading. if after a day one reads 60%, i mark it with a (+2) so i know to add that on when reading it. i'm sure it's far from a perfect science but it seems to work for cheap hygrometers.