UPDATE
I have added a Phase II and Accusize holder. Accusize seems to be the Shars of Canada. The holder was available through Amazon.
The Accusize is the only holder to use a smaller 8mm set screw. The screw has a loose fit. The Phase II 10mm set screw fit is good but the 5mm hex key sockets are tight, two would not accept a 5mm hex key. A 3/16" key can be used but is a loose fit that would cause problems after a while. The set screws for both holders are candidates for replacement.
Phase II - Fit and finish falls in-between the Shars & CDCO. Of the six holders this one is the smallest over all.
Accusize - Finish wise it looks great. Unfortunately the bottom of the slot for the tool is not flat. There is a hump in the middle with a twist. Measurements at the right = 0.000", middle = +0.002", Left = -0.002". In the short direction it varied between 0.002" to 0.003".
Below is an updated matrix. I expanded the rows to be able to more easily compare the different attributes of each holder. I also added the measurements of the dovetail. The width measurement is taken in-between precision ground pins set at each side of the dovetail. Both pins are 0.2504" in diameter.
In addition I have also added repeatability data for a no-name import piston style QCTP left over from my original lathe. Because the piston style QCTP pushes away I added measurement data in the Z direction.
One thing to mention about the piston style QCTP is that if one just drops a in holder and tightens some of the holders were susceptible to locking with the holder slightly askew. To get good measurements it was important to apply some back or forward pressure into the dovetail so it would seat square each time. The holders with the loosest fit were the most susceptible but felt better locked in. Holders that were snug were less susceptible but didn't feel well locked in.
I will also mention that a few of my other CDCO holders will not fit in the piston style QCTP but they all fit in the wedge style.