Got a small gift and decided to splurge on the hardwood laminate version of the Kun collapsible shoulder rest. I was mainly interested in getting a more solid platform (though the regular Kun collapsible is my default and does the job pretty well). It definitely is sturdier, but an unexpected positive is that I actually notice that the hardwood shoulder rest definitely seems to allow a tiny bit more clarity to shine through than the all plastic one. At first I wondered if I was imagining it, but I tried it out on a couple of my other fiddles to the same result. It's very, very subtle--I would turn to setup and strings first if I were looking for more brilliance--but it's definitely there. The closest I can liken it to is the difference that fossilized walrus ivory bridge pins make on a guitar.
My theory is that I am hearing the difference in vibration through the hardwood and brass that make up the shoulder rest, as opposed to polymer (screws are brass on this, not the rest of the hardware like on the hardwood version). I didn't see any other comments about this phenomenon on the reviews of the violin shoulder rest, but after I noticed the difference, I found a review for the viola version of the rest on Shar's website that commented on the additional clarity/brilliance.
In any case, I recommend it highly for its stability, solidness of construction, and the tiny bit of clarity it adds contrasted with the standard Kun collapsible. Don't know that I would have bought it in the first place if I didn't have a gift certificate (and undoubtedly many might feel that the price of the hardwood version negates the subtle benefits it brings with it over the all-polymer version) but I am really happy with it.