Ive seen quite a few of those Leupold for sale lately.My M5 is great optics,5-25 model but very large.I would really like to look through the 3-18 sounds perfect.I like mils used for last 15+ years.Dont believe they make a 4-20 atacr.They make a 4-16,sounds real good.My March 3-24x52,is realisticly good to 20x,low pro turrets,light good ZS,and been on tough hunts and rough rig use 6-7 years on light 338 NM.ZC I bet is great but heaviest of bunch at 34 oz. The leupold has good turrets and ZS.Id like to view a new March.If your thinking ZC, then you should consider TT315M,27 oz.