I have used mine for three years and quite like it. It is small with good optical quality. The rangefinder effectively works out to 700 yards, but don't count on it to go much more than that.
I love mine, it's the one with TBR. I have ranged trees as far as 830 yards. My primary use for it is bowhunting but I did use it on my sheep hunt and it helped me anchor a ram at 319 yards - one shot and drop.
I had one of the original (non TBR) models and absolutely hated the thing. I couldn't get a range past 400 yds hardly ever. I've heard much better results with the TBR ones so if you do get one, I would make sure it is a newer one.
I bought both the 1000 TBR and Vortex to do my own comparison. I really wanted the Vortex to win out since I love their optics but the unit went bad after the first session and didn't give accurate ranges to known objects (definitely not a knock on Vortex, anybody who manufactures complex electronic devices is bound to have a few lemons). Instead of utilizing the warranty, I just returned it especially since the Leupold worked so well and better all around in my opinion. One thing I did notice when the Vortex unit worked was that the Leupold computed the range noticeably faster. The Leupold also offers more fine tuning with the TBR function, especially for rifles. As others have said, definitely get the model with the TBR function if you go this route.
Love mine. I originally bought the vortex and my guide had Leupold. Side by side in the field the Leupold was much better for a number of reasons - better glass, faster to range and more importantly required fewer clicks to range items. The last one made a big difference when elk hunting and you needed to range a number of objects quickly. After the week long hunt I returned my vortex and bought the Leupold.