I grabbed an OpTech Bino/Cam harness a few weeks ago, and I put on a few miles with it yesterday. It's not too bad - definitely better than a traditional strap. I like the fact that it attaches to the camera with quick-release buckles. I think I might pick up a regular strap that's compatible with these same buckles, because it's a little awkward to put on and take off.
The Cotton Carriers look interesting, but I can't quite picture how the tether works (I really don't want to have my camera be completely loose while I'm hiking if I can avoid it), and I'm not crazy about the fact that the mount uses the tripod mount. I can see all the adapters they've got (some pieces sold separately), but I didn't see anything for a TrekPod.
I agree that it would be nice to have something that took advantage of the sternum strap, but I guess I'd almost like to see something a little simpler -- just a hook of some sort to tie the camera in place so it doesn't bounce all over when I'm hiking.
The more intricate the device gets, the more of a pain it is to gear up / gear down. I even found myself yesterday trying to keep track of what straps went on in what order to I could take everything off without turning into a tangled mess.