I've had pretty good luck with CDCO and Shars AXA and BXA wedge-type QCTPs. They hold tightly and reasonably reproducibly. I think you'll find a world of difference between the piston type and the wedge type, no matter what brand you go with ... especially in the CXA size! And it's more than likely that you'll be able to continue using you existing tool holders, no matter which brand of "head" you buy.