I went with the 43x. I love everything about the gun except for one thing. I get the worst slide bite with it, like blood splatter on my face and glasses bad. It doesn't appear to be much of an issue for other people out there. After many internet searches I'm unable to find an aftermarket beavertail. The narrow width of the frame allows my right thumb knuckle to roll around and up the side of the beavertail that comes on the gun, it's just too narrow. No matter how I grip the 43x I get cut over and over again. Anyway, make sure the gun fits your hand before you buy.