Should I upgrade paint on aluminum boat?

Nope! 

More tore up the better!

What kind of boat and what's the current finish? I've pondered this a bit with my Lund. They are factory powder coated so the most I would do is scuff it down, epoxy + urethane it...But I own a paint shop and still don't even really want to do it quite honestly. 

I had one repainted. If you find the right shop it looks nice. Forget the bottom of the hull though, that paint is expensive. Just do the sides and the transom.