Sheldon asked a great question for the Dynamics GP 2013 Upgrade: Are you still using converted security roles in your GP security?.
I can tell you that the answer is yes, a lot of you are.
Dynamics GP 2013 Upgrade: Are you still using converted security roles in your GP security?
Install, Upgrade & AdminGP 2013
Archived post from 2013. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.