Archery rangefinders - what to look for?

[ZDR]

qwik update...I ended up purchasing a Vortex Razor 4000 from @S&S Archery (Rob) . He uses the same RF and was able to give me some great feedback/advice on it. He also gives Roksliders a 10% discount which I didnt expect. I received it Friday just before my wife and I took off for a weekend camping trip to the Rio Chama. My first impressions of the 4K is it is built like a tank...solid with a great texture, kind of like non-skid. Its water proof, the menus are intuitive to go through and the 7x optics are spectacular. Very clear and bright. Here is a few pics though it but they dont do the optics justice:

Ranged this mesa at 2960 tyds

this at 929 yds


Most importantly though, so far, I think it is perfect for bowhunting and 3D. I had my bow and a target with me and it was spot on to my sights between 20 and 85yds. The optics are good enough I'm not sure I will carry my binos on 3Ds where the distance wont exceed 60yds.
This was one of those purchases that exceeds my initial expectations.