CG,
The only higher priced Sightron I tried was the $500 S III LR 8x42. Stet, from here, bought one a couple of years ago. My opinion was that it was at the same performance level as the other open-bridge ED binoculars that have been popular over the last few years (Zen Ray ED series, Vortex Talon, etc...). In other words it is impressive optically. I didn't find any mechanical issues in Stet's model but, if I remember correctly, he was bothered by the fact that it turned with a little more resistance in one direction rather than the other. I noticed it but wasn't bothered by it.
The only reason I didn't feel the need to comment further was because of the price and one spec issue. The regular price is over $500. Why would I want to spend that much when I can get the same performance from a $400 Zen Ray or Vortex? The "spec issue" was the field of view. It was good at 393 feet but not as wide as others offered at less of a price.
I don't remember if anyone tried the S III Magnesium models. Looking at the specs though and, again, the price I would question what the attraction would be. The 8x32 model has the exact same specs as the SII 8x32. The field of view is the same. Listed eye relief is about the same. The big "draw" to it from the product description seems to be the use of magnesium in the housing to reduce weight and yet it has a listed 19.3 ounce weight. That is 2 ounces heavier than the SII.
Admittedly, I haven't tried the Magnesium models so maybe they have spectacular optical performance. I don't see, on paper, how they would separate themselves from anything else at or below their price point though. Even if they did have fantastic optical performance (better than the SII at least) then they are still priced at or above $400 and I haven't seen any sales on them. There are plenty of excellent 8x32s out there at or below that price point these days.
No, the draw to the SII Blue Sky is somewhat unique. Its optical performance is fairly unique primarily because of its price. I believe a large part of that optical performance is the result of the length of the binocular specifically because it is an 8x32 model. I haven't found another 8x32 as long as it is. I believe that length contributes largely to the well-corrected image quality. That longer physical length also contributes to how comfortable it is to hold. my larger than average hands comfortably fit around its open-bridged frame.
So, in this world where we keep trying to make the lightest, most compact mid and full sized binoculars there has to be somewhat trade-off. Happily the Sightron bucks that trend and provides excellent optical performance for the price.
I will never sell mine.
