As with riflescopes, the more you spend (generally) the more you get. However, there are some very fine spotting scopes in the medium price range. If the scope will be used mainly at the range I would give these features some serious consideration:

-Go at least 60 mm on the objective lense. More light = better view.
-" Armor" coating with a rubber surface makes them easier to grip.
-Straight through or angled eyepiece. Straight is easier to find the object being viewed but angled is more comfortable.
-Eyepiece. Not all eyepieces are the same. If you choose a medium or upper level price range there will be a choice of eyepieces. Some fixed power, some zoom. If you go zoom make sure it has plenty of eye relief and is wide angle.
-Tripod. A good quality tripod will enhance the use of the scope and its view.
-Lense coatings = more crisp image.
-Waterproof?
-Size. If the scope will mainly be used at the range then size is of no consequence. But if you are going to tote the thing into a deer stand then smaller size is handy.
-Price. You can spend anywhere from $200 to as much as you can afford.

That being said, I really like the Nikon Fieldscope. An excellent medium price range scope in a smaller size with all the view of most of the bigger scopes. Kowa also makes excellent scopes. I know Zeiss and Swarovski have put out new 80 & 85mm scopes recently.

I would suggest looking through as many scopes as you can. Preferable side by side, if possible. Some just " fit" better, are easier to use, and feel right compared to others. And, as has been said before, everyone' s eyes use light differently.

Take a look at www.betterviewdesired.com for non-sponsored reivews on optics of all kinds. You may also want to call Christophers for advice- the owner was very friendly and helpful when I purchased my scope. www.astronomics.com follow the link for binos and spotting scopes.

Hope this helps.