I spent a few hours yesterday trying to get my TCPS set just right with less than stellar results when shooting 4 TB. It doesn't help that I have all the patience of Jack Kevorkian.

On a whim, I shot the same scene using the exact same settings only I did it with 6 TB. The results were almost perfect. The only aberation I could find when I tested it was on the floor when I had square black and white marble tile. The 9 tiles directly around the tripod showed some very minor ghosting but other than that, perfection. On a carpetted or non-black white tile, I couldn't see any problems with the image at all, except my white balance on the ceiling blows goats.

Thought this might come in handy some time for new folks (like me).

I got this tripod nadir area with a TCPshort - 4 images around.  Clean stitch too.  Secret is getting the nodal point correctly aligned. And parallax (left to right) alignment fixed.  This is a screen capture while previewing it in panoweaver.  The red marks are denoting the convergence of the 4 images in the nadir area.  In mid center notice the single screw.. shown 4 times.