After some experimentation, years ago.......I keep everything as close to 65% as possible.....if anything I use 65% as the upper limit and I am fine if they are anywhere between 62-65%.
IMHO, the cigars just smoke better at this lower RH, than they do at 70%
It is definitely personal preference.....one of my best smoking friends keeps all of his sticks at 70% and is just as convinced of that number as I am of 65%.
One thing for me that has made a difference is keeping all my hygrometers calibrated....I use the digital type that you can reset after the bag test. I numbered all of mine and keep a little notebook log recording the calibration date and setting required to bring it in line. Thanks to my obsession with collecting sticks, I currently have 7 hygrometers to keep track of, so having a set time to recalibrate (every 3 months) and a logbook made things easier for me.
Some will probably think I'm being too anal about this, but it is just the old power plant operator leaking out of me. After spending my entire adult working career (29 years) relying on gauges to tell me what is going on with the generating equipment, I realized the necessity of instrumentation that I know is accurate.:tu
Mark