I started Production Optics with a Vortex Viper and then learned window size was everything with these optics. That led me to the 2.5 MOA Deltapoint Pro, much bigger window but for whatever reason their dot was terrible for my astigmatism and all I saw was. a kidney shaped flare. From there I went to the FTP Alpha Optic 2 which was a night and day upgrade from the Vortex and a nice upgrade from the dpp, slightly taller window and the 6 MOA dot was much quicker for me. The other thing much nicer on the Alpha Optic is the controls, I never liked the dot brightness controls on the DPP.
I now have the Alpha Optic 2 on both of my Open guns, haven't tried the Alpha 3 because it won't fit my mounts due to the blast shield. When my new open gun arrives I am going to try the Alpha 3 in 8 MOA.