Focus Rings

I am moving up from a Micr 4/3 systems where I always let the camera focus. I bought prime lenses with the intent to continue this practice. Does anyone else not use focus gears? Or is there a reason I should not considering shooting this way?

I am shooting a d7100 in a Nauticam housing.

Most shooters including myself use autofocus on DSLRs for still shooting. You can always fine tune your focus by using focus lock or back button focus and rocking the camera. The exception for me is the 100mm macro. I use a focus gear on it along with autofocus.