The venom is WAY easier for battery replacement. Viper access is on the bottom requiring removal of the sight from the mount. The venom is from the top. As far as 3 or 6 moa...u wont really notice any difference at turkey ranges. I have the venom 6moa on my gun now. Got a really good supper saver deal for it from optics planet so went with the 6. I really like it.