I have been a long time appreciator of the Travelite and Nikon reverse porros for a very long time, back to the early 90s when I picked up a used pair of II's in Cambridge, which I sadly lost track of somewhere along the way. The Travelite is sort of the VW Bug/Honda Civic of binoculars, which is saying a lot. I have given many pairs away.
I have sent several pairs of Travelites back to Nikon over the years for repairs over the years. They always actually repaired them - except the last time, when a new replacement pair arrived. I was struck by a very good image, but they just felt cheaper and more disposable, and I gave them to a friend (as a side note I noted that they were now made in China). Part of the fun is using a quality piece of gear, and life is too short to waste on crap.
I have always been intrigued by the Better View Desired reviews of the Diplomat, which seem to be borderline unobtanium because I never see them on ebay or elsewhere. A nice pair of Mountaineer I's showed up a year or two ago, and I have really loved them. I have thought they are perhaps essentially waterproof Diplomats.
These Mountaineer II's showed up, and I really love them. They are even better than the I's (which themselves are a clear step up from the Travelites). They are chunky as hell. I just bought a pair for my brother, who runs a fire ladder truck, and he said they were going in his go bag. That kind of tough - heavy cast alum frame, etc.. The heaviness is an asset as they stabilize the glasses for clearer viewing.
I was unaware of the Prostaffs, and they sound intriguing. Polycarbonate is not all bad, with bounce replacing stiffness/brittleness. I am curious about feel and optical quality. If they are similar to that last pair of Travelites, I'll pass.
The B and L 7x26 series 4's from the mid- and late 90s are yet another branch...to be discussed elsewhere.
I am waiting to get my pair of 8x25 Zeiss Victory's to see how they fare against the Mountaineer II's...