We have a sig Kilo 850, and it does okay at 500 yardsish ranges depending on the conditions. What I like about it, and the 2000 and 2400 I have used, is they are super fast in terms of re-ranging. If you miss a target, you can hit it again super quick. What I don't like is the glass, especially on the 850. Even if you don't use it as an observation device, my son's 850 becomes useless way too early because the view is so dark, you can't see to range, especially in bad conditions. The 2000 is better, and the 2400 better still, but the Leica RF's are top shelf in that regard, to my eyes, they have no peer in the current pocket RF's as far as glass goes. I was using my 2700 last night well past sunset (we were predator hunting so we stayed into the night), and it was clear and bright well past 30 minutes past sunset. In terms of ranging, hand held I was hitting tree foliage on a far ridge at over 2700 yards, but conditions have to be just right to pull that off in full sun.