Walnut Horns,
I recently spoke to Steve Dobbins about his plinth. He uses a constrained layer approach similar to what I believe Artisan Fidelity uses.
Right, both designers use constrained layer damping construction methods.
Does anyone know what, if any, differences there may be in SQ?
A couple of years ago, I purchased a second hand modified Dobbins 301 which although I thoroughly enjoyed, ultimately sold to a friend after arrival of my Artisan Fidelity Garrard 301 Statement. IMO, the later unquestionably exceeded my former 301 both in playback and finish, and as a result I simply no longer listened to it. Bear in mind, several other turntables occupy my space as well which share the spotlight! Admittedly, sometimes I want to keep all of my cherished audiophile possessions, then I stop to remind myself that often a man requires more than one passion to keep him invigorated.
With these finished models, its honestly challenging to try and answer your direct question in detail, as the decks themselves are just different animals. Bear in mind, I was not solely comparing plinth vs. plinth in my system, but totally separate turntable models altogether, which just so happen to share the same base Garrard 301 design platform and idler drive type of layout.
Really, after having owned numerous lovely analog machines over the decades, many designs at this level remain quite exceptional, but sometimes you just have to find the right one(s) best suited for you and settle in for the long haul.