I've smoked some wonderful 40+ year old cigars thanks to CigSid, and can attest to his storage methods. They were, in a word...perfect. At least to my fried taste buds.
Recently, I've noticed my cigars seemed just a bit 'off' and I discovered that the controller in my cabinet was off, by about 5 points (low). Frustrating, as this is the controller that went through a full calibration and rebuild by the manufacturer about four years ago. I'm currently installing a new controller and slightly larger circulation fans that will run on a timer rather than when the humidifiers kick on. I'm also going to be using a couple SensorPush monitors that have just been salt tested and calibrated to keep a watchful eye on things.
Back on topic, my setpoint has been 65% / 68F for some time, and I have great results in the storage of my cigars. I dry box at 60-62% for a few days before smoking. Some have spent 15+ years in my cabinet. I won't pretend that I know all things but what I do know is how my cigars taste and I'm very happy with my results. Wouldn't store less than 65% long term, on a dare.
As they say, one man's opinion.....