I suppose that if you have lefties and righties shooting the same gun, it would be nice. As Dale has pointed out the standard one will fit both left or right, but just one of them at a time. I do not know their construction, but the more weight you add to the hammer, the longer the lock time is. The lock time is how long it takes for the hammer to travel from the cocked position to the firing pin striking the primer. I am not sure about hammer force; the hammer would travel slower, but will carry more weight to strike the firing pin with. Just some thoughts, to each their own.