I used the Vortex Ranger yesterday while out shooting. It's good out to 600 yards but didn't get any ranges after that. I tried big rocks, trees, side hills but it wouldn't give me anything passed 600. And I'm fine with that since I kill most big game animals at 400 or less and try to always get with in 200. My only negitive I found with it is this. When you push the button to get the cross hairs up to mark the target you want a range on you push the button again to get the range and the cross hairs go away while the Ranger gets the yardage. I don't like that. I'm used to having the cross hairs on the screen while the laser is getting the yardage so I can consentrate on keeping the cross hairs still on the target. When the cross hairs go away I don't have reference point to keep the range finder still. Other then that I'm happy with it. I have to look to see if there is an option to keep the cross hairs on the whole time. I hope so.