lI will say after having and using both side by side, the Leica only gives angle corrected range to 875 yards. The Bushnell ARC gives ranges farther in daylight conditions. I am now moving to a Terrapin. If your goal is ranging pinpoint accuracy from 900 and in in good conditions then the Leica 1600B cannot be beat, plus having atmo data in case your Kestrel takes a shit then you are covered. If ranging large objects or the berm behind your target to 1300 yards with excellent accuracy then Bushnell ARC 1600 is your tool.
Honestly I ranged to 1656 with my Leica on a sunny day and 1890 with my Bushnell ARC's but do not count on that being the norm.
If it were my choice I would buy the B version for the angle and atmospheric data alone. The ballistic engine was worthless and I knew that going in. I run a ballistic computer and back up dope cards. I have back ups for my back ups.