Don't bother with the Vortex, Leupold, or other low end units. Some of them range very well, but all of them have crap optics. Not much fun to be trying to range an animal early in the morning or late evening and not even be able to see it through your rangefinder, but you can see it through your binocs and with the naked eye, then nothing but dark smudgy looking things through the RF. I've been pretty happy with Leica. I had a CRF 1200 that worked well, wanted the angle comp, so I sold it and eventually went with the 1600B. I first tried the Leupold RX 1000i and just couldn't settle for those optics. Not a bad unit if that is what your price range dictates, but if you can afford something better, I'd do it.
