Ball links will never give you slop. Clevises routinely develop slop, and need to be dealt with, as evidenced by the replies above. So, if you don't mind spending a little more, the ball links will give you longer service, with less fuss, and can tolerate linkages with larger angle offsets if need be. The Clevises are cheaper, will develop slop, and will need the arm to be replaced or modified every so often.

Basically;

Ball links = no slop, more money
Clevises = less money, will develop slop over time
or
more money, less time
more time, less money

Why does everything seem to come down to this

I personally only use ball links on my larger planes for control surfaces, especially when I use 3D rates. And on smaller ones it really depends on the airplane, and whether or not its really required.