Had an opportunity to compare the 1600 with the 1600B while checking drops on a newly built 338 Edge. My 1600 was purchased in 2006. The 1600B was purchased in 2015. Max ranging distance on both was equal. Ranged to 1500 yards when the sun was behind a cloud. However, the 1600 would range reliably, at decent distances, only on the dark side of the juniper trees. The 1600B would range on anything I pointed it at. I was severely impressed when I could range bare shale at 1400. That is impossible with the 1600. Additionally the 1600B is much, much better glass and the ranging square and numbers are much easier to read. I'll be moving up to the "B" one of these days.