At the local Cabela's there are two mounted black bears with dark fur. For some reason the Bushnell G Force DX rangefinder in the store refuses to give a range to either of them, but the brown bear with lighter fur beside them is fine, as is anywhere else in the store. Interestingly none of the other rangefinders (Leupold, Vortex) have a problem with those bears, which sort of turned me off the Bushnell.
My only beef with the Vortex 1000 is that it's noticeably slow to return a reading. The Vortex 1500 is way faster, and quite a bit more expensive.
Having tried the Kilo 2000, the auto-brightness feature is pretty sweet.