I had a lieca 1200 It wouldn't range dark objects in low light conditions every time. My dad has a Leupold and it will range up to about 800 yards most of the time, but not every time. I use a nikon monarch 1200 and I've ranged things at 1100. I hunt with a guy that has a bushnell and wasn't too impressed. What I was getting at in my first comment was most range finders will not range the target every time at those distances. Every time key word. They will range at the yardage they are rated for in perfect conditions.
To clarify, I only recommend the Elite 1500 rangefinder from Bushnell. The other Bushy rangefinders are pretty lackluster, IMO. The Elite is not great optically, but it is good enough. My friend's Leica 1200 blows the Elite out of the water as a monocular. The Elite is also kind of bulky. What the Elite does do is range a long ways accurately. It consistently gets longer readings faster than the Leica, although the Leica is pretty good too. I think the Swaro, Leica, Zeiss, and Bushy Elite are the best long-range rangefinders available to hunters. I haven't used any of the high-end Nikons, though.
Eventually I am going to move to a binocular/rangefinder combo as the ergonomics improve. So far I really like the Zeiss combo the best. I really hope Vortex comes out with one soon.