Both really nice scopes for the money. The Zeiss has an advertised 65 moa of total elevation travel, would definitely want a 20moa base if you are going to dial out to 1000y. For the 6.5x47 my ballistic calc calls for about 31moa of up at 1k with a 139g scenar at 2700fps. Too close without a base, IMO. The SFP Sightron has around 100 moa, and the FFP Sightron has around 80 moa of travel. As far as tracking, the SIIIs are known to be spot on reliable with tracking. I haven't heard of issues with Zeiss, but it probably isn't quite as adept to being dialed up and down constantly like the Sightron is. Haven't looked through HD5 yet, they now have the Lou Tec coatings and as supposed to be rockin glass. The Sightrons are among the best glass around 1k in a tactical scope also. Tough choice, but for dialing a lot, I'd choose the SIII.