Even custom cams aren't perfect

The problem with gear drives are they transmit harmonic vibrations from the cam, crank that a chain absorbs. That's why a Jesel belt drive is so good besides being adjustable the belt absorbs more than the chain does. Gear drives are fine if you are running low lift, weak springs, engines have been running them forever, but when you get up into .650, .750 lift triple springs the cam transmits a lot of harmonic vibrations that are sent to the crank and all over the valve train, and from the crank to the cam. Everybody knows that vibrations are bad that's why you balance your motor.
Just my 2 cents on gear drives.