I have the Nikon harness and I really like it. The guy at the Bass Pro counter said he had tried several and ended up buying the Nikon harness for all his binoculars. That said, I don't have experience with any of the others. I think I dropped $20 for what it is worth. If you don't like them you aren't out too awfully much.
X2^^^^^^^^
I never could get used to the binos being onto chest. I always had the fear in the back of my mind that my string was gonna hit it somehow. Same in the tree. One of the first things I do is take em off and hang em up. If I'm doing a lot of stalking I do the same thing Eric does and use a strap over one shoulder.
I have the Butler Creek version and it serves the purpose. I'm like Milo though and don't really care for them on my chest and usually sling them over a shoulder...
I've got a Badlands Harness. It's got elastic straps, so the binos tend to sit a little lower and don't get in the way of my shooting. I don't like that the binos bounce when you walk though. They serve their purpose, but I don't use them other than 3D and scouting.