The nice thing about using su to root in a terminal is that you can run many commands and do your housekeeping, installations, etc., without constantly typing in your password. That accursed Ubuntu practice of using sudo, in contrast, requires doing it for every new command (though I think there is some way of making your permissions last longer but it's obscure).
I don't remember the last time I loggeed into the root account. Even in a new installation when I have a lot of root things to do, I log into my user account, su to root, and do everything I need to do and then exit back to user so I can actually use the computer.<g>
--GrannyGeek