I have been shooting the XR-3RED grip on NMBHs for the last 6 years. I have large hands. I like thin grips on this grip frame, like the Eagle Grips Gunfighter grips, smooth for high recoil guns, checkered for low recoil.
I also have a Bisley, which also has Gunfighter grips. Not bad, but for my large hands, the hammer spur is a little low. I have handled the XR-3 grips on the 50th Anniversary model, and I like them. I would like to get one, esp. if they make it in stainless.