That is why I like beads so much. All you need to do is "activate" a higher percentage of beads and voilĂ , the relative humidity raises accordingly.
For me though, it does also depends on the quality of the humidor and its seal. Some of my desktops are very high end and they keep RH levels better than my cheaper ones. The wineador is somewhat harder to maintain but that is probably because it's only half full. Now the coolers are the easiest to care for as they almost don't even need a push in the drier months to remain at 65%, unless opened often. I do have Spanish Cedar lining in my coolers that helps maintain RH even if opened daily.