Unless you're racing a stock class, I can't understand why anybody would want to spend the money on Mercury pistons. The Wizard pistons are awesome and I know Nick Winski has put quite a few in various motors with great success. None have come apart. They're very consistent out of the box, but like always, match up your rods, pistons, and wrist pins to get the most balance unless you're cutting them.
The Wizard piston is made by Weisco too so it's the same as mercury with sufficiently different design features to not upset Mercury (although I'm sure it's upsetting them anyway). The way the Wizard piston is cut will help it run cooler and distort less due to heat. Great piston.