I was looking at reviews of the MGW after reading this warning from MGW:
Tool is not designed to remove extremely tight factory rear sights. Sight tool is intended to install and adjust Tritium Night Sights.
Reading through the reviews, I didn't see anyone had an issue with the rear sight, but...
I was able to loosen the set screw pretty easily with a 1/16" Allen wrench without heat. Getting the site to come off is another. I'm probably going to have to take mine to someone with the proper tools before I damage it too badly.
When I had my Ruger SR9c, I used the Shaggy by Custom Carry Concepts. Great holster. After getting my M&P 40c, I put in an order for the George by JM Custom Kydex. Still waiting on that one.