A better tolerance test (at least for me) that is not affected by overhangs at all. The pins are held in place by a band in the center that has a 1mm clearance all around, and the pins can be turned free with an 8mm Allen wrench. Edges are chamfered all around to prevent 1st layer issues from affecting your results.
An added benefit of the clearance around the center band is that the pins can be moved along the Z axis a little bit as well. Pins that cannot be freed by the Allen wrench alone can be tapped gently from either side with a small hammer to aid in freeing them.
After printing the tolerance test from Maker's Muse, I found that the print was binding on the overhangs while the actual pin sections could turn freely, so I designed this one in 123D to overcome those issues. On the Maker's Muse model, I could get the 0.35mm free, but nothing smaller. With this model I can get the 0.2mm free with a little effort, and the 0.15mm with some percussive persuasion...
UPDATE I decided to whip it up in OpenSCAD as well. It can now be customised to your own specifications!