One of the things about vinyl playback is the quality of the turntable, arm, cart, & RIAA preamp.
I admit to having bought one of those over-built high mass turntables (second hand). It was from Germany's oldest turntable manufacturer (been making turntables since the early 70's) so I figured they at least knew what they were doing rather than being some new vinyl-bandwagon-hopping new company. Still, I'm sure it goes beyond what it needs to in order to realize decent vinyl performance (and it certainly did seem to make improvements over my previous micro seiki). But I also have no problem believing it's outperformed in some ways by well designed turntables that are much cheaper.
The thing that kills me watching the audiophile turntable market is this apparent "If X is good, the more X must be better."
So yeah, isolating the vinyl signal from additional spurious vibration is a good thing, and that's what turntable engineers have been doing for a long time.
But as in all things audiophile it's taken to crazy extremes. It starts with a regular sized turntable with a metal platter. Then the next model the platter is twice as thick. Then you have a 30lb platter, then 50 lb, then 80 lb - all in the name of "isolation." Then the massive platters are placed on isolation platforms of heroic construction - like layers of coliseum pillars with vibration isolation separating each layer. Slap on an $80,000 - $200,000 price tag and there you go! It's like, my god, just how much isolation is enough? Surely these things were well in to the "doesn't make any more audible difference" well before these massive structures were designed.
But it's sold in the same sense of "you can always do better, and you can always hear a difference." Even if in engineering/sonic terms it stopped making sense long ago.
Reminds me of the audiophile urge to continually tweak via ever more expensive cables, shielding, isolation devices, cable risers etc, to "lower the noise floor more each time." It's as if the ability to lower some mythical "noise floor" is infinite and human hearing has some infinite ability
to keep hearing down further. (Which is why this is so well explained as being people's imagination - our hearing isn't infinite, but our ability to imagine changes seems to be).