Sort lines - Vim Tips Wiki:

Vim has a very powerful built-in sort utility, or it can interface with an external one. In order to keep only unique lines in Vim, you would:

:{range}sort u

Yes, it's that simple.

So to answer my question, yes, :% sort is all you really need to know.  Wow.  Feeling like I got my donation's worth on this one.  ;^)