I bought both harnesses for flexibility in who uses it. We've only dry-fit so far, but my well-endowed daughter definitely has a preference for the S-harness. It does what it's supposed to. If I have one gripe with both, it's that the sternum strap and the pockets can't occupy the same real estate. So you end up with pockets above your sternum strap, wherever you put that. Feels a little high. I may supplement with auxiliary pockets because there is plenty of space on the daisy chain below.
I changed out the regular shoulder yoke to the larger version and was disappointed to find the replacement yoke didn't have a whistle on the sternum strap. That won't interfere with how the yoke fits but it's annoying as I originally wanted the large yoke but was told by the Six Moon's rep that the regular would be better...it wasn't (and I had to pay additional shipping to get what I wanted to begin with). In the end the pack will be fine but having to pay extra $$$ wasn't something I appreciated having to do.
So far the harness is comfortable and fits good but the harness pouches are useless. They sit to high on the shoulder and are to small for water bottles. SMD should consider making these pouches removable.