I bought a Vortex for my G19 and Leupold Deltapoint for the G40. I recently took advantage of a Burris promotion and got my free Fast Fire III yesterday. Although I haven't a gun to put it on, it seems like the FF is a better rig than the Vortex. Simple on off and brightness adjustments are the primary reason I say this. The Leupold is the cream of the crop with motion sensing activation and I was able to buy it on Ebay for only $339 shipped.