I use binoculars primarily for hunting. Over the years I have owned a few cheap binos and my usual gripe is twofold - they lack sharpness and do not hold up to long-term (ab)use. I finally decided to get something good, but could not mentally justify the cost of brands S, Z, or L. The salesman let me look through several pairs, and the Vortex Viper 10x42 binocular stood out as exceptional in sharpness and ease of focus. I decided that the price was worth it, especially considering they are Japan-made. They are light and decently compact; time will tell how they hold up. Nice touches include lens caps that are attached to the body and a strap with a perfectly comfortable neck band. Not merely extremely comfortable, I actually often cannot feel the weight of the binoculars around my neck. Eye relief is long and the eyecups are adjustable; I have never peered through binoculars that were easier on the eyes, and this is important for some of us hunters that will sit for hours on end with the glasses glued to our eyeballs.
There are many questions that still remain, however. Even though I've had and have heavily used the Vipers for a couple of months now, I still don't know about their long-term durability. I find that many binoculars tend to lose the alignment of their barrels over time and frustrate the user with double vision. For me, this is the biggest concern, and only after some years of use can I be confident of durability. Vortex supposedly offers a semi-unconditional guarantee on the binoculars (transferable with no receipt required) which is very attractive.
For the time being, though, this binocular is just right. Not only is it very sharp and easy to focus, but the adjustable eyecups are about the most comfortable I've ever experienced and the neck strap is so comfortable I often must look down to see if I'm wearing the things. Admittedly, such little features do not in themselves justify a $500+ price tag, but they sure do a very nice job of completing a fine package. Touches like this do show attention to detail, and possibly even suggests that someone in the development/designing/engineering department might be an actual user of the equipment (s)he is designing!
In summary - very sharp and bright, lens caps that stay attached, comfortable eyecups combined with good eye relief, and a neck strap that simply cannot be improved upon. With luck, it will last me many years.