I love adjustable stems. The option of pulling it up or down is awesome. However over the past two decades I have never adjusted my stem height. I always have the stem set as low as possible to get into a "tuck" type of riding position ( which is aerodynamic ). Most riders are the same as me having the stem set as low as possible. I have noticed riders with back problems set their stems high, so as to keep their back straight. Overall, I have only seen two setting for stems, super low & super high. Strange but interesting.