I suck at ranging distances. That's my one real weakness. As much as I prefer to just be able to look and get a workable distance in my head, I'm usually way off. Either way to close or way too far away. And while I wish I were better at it, that is one of my real weaknesses shooting. And why I have accepted that fact (after 40+ years of denial), I bought a Halo (XRay) 600 yard rangefinder. What I like about it that many other rangefinders don't have, is that it has a slope/angle compensation. That is mandantory for where I live. It's not uncommon to have 40 and 60* angle differences from me to a target. So far, the halo hasn't let me down. It does use an oddball size battery though. And I bought a set of rechargables and a charger from batteryjunction.com and now I don't have to worry about finding batteries either. I have been known to spray paint numbers on trees if it's a place that I know that I'm going to be hunting at well in advance. I dont' think I'd want to paint up a place close to season opener though.