Very good - i give it a b+ - Vortex Viper HD 15-45x 65mm Spotting Scope

The Viper is a very good mid-price, mid-range spotting scope. When used to locate hits on paper targets it's excellent at 100 yards, good at 200 yards, and just adequate for large caliber purposes at 300 yards.
The HD glass is quite good; crisp and bright images.
The focus ring works well (using a very stable base/tripod helps a lot).
The ability to easily rotate the scope around its mounting point/base is actually a useful feature.
The limiting attributes are, naturally, it's max 45x magnification and 65mm objective.