SuperSU Pro adds the following features to your SuperSU installation:
— OTA survival mode (no guarantees)
— Full color-coded command content logging (input/output/error)
— Per-app logging configuration
— Per-app user override
— PIN protection
See the SuperSU app description for further details on SuperSU.
Note that SuperSU Pro is rarely updated — most of the updated code goes directly into the main SuperSU app. That is the one you need to update.