I am an amatuer photoshopper. not a pro. but usually when working with ps and the stylus, I keep left hand on the keyboard and right hand does the stylus. so all the shortcuts will be handled by the left hand like T for text, M for selection etc... so I never use the buttons on the wacom at all. i mean buttons on the pad which require right hand for operation but right hand already holds the pen. its little tricky. but with a 2K screen and high resolution mouse, I always feel that I need a high res tablet. I mean cover the entire screen without moving the wrist. but it is not possible on the pad.
coming to your question. its way more precise than using mouse. it also supports angle detection, pressure detection etc... which are very useful and cant be done using mouse.