Turntable isolation

My last turntable was a VPI HW19 MK4 .... with the springs.  It's isolation from footfalls was terrible on wood framed floor. Are the modern tables with sorbothane feet better at isolating?
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I can’t think of a single turntable, modern or otherwise, that uses Sorbothane feet. Maybe there is one somewhere.
That's why I am in the basement. Concrete floors 6 inches thick. By choice. My large reception rooms with marble fireplaces lie unused.
I’m not sure that any table can withstand very springy floors. My Linn was horrible in this regard, but totally cured by a wall shelf. My current Basis is better than the Linn, but one would have to tread very, very lightly. Again - wall shelf mounting cured the problem. My point being, if you are having problems with the VPI, you are likely to have problems with almost any table in the same location. IMO. I think the Music Hall tables use Sorbothane between the layers of the plinths, but I’m not sure about the feet. BTW, if you are looking for a better turntable location, try placing a half glass of water on the intended shelf and walk past it. The movement of the water, or lack thereof, is not a bad indicator of how much floor vibration is transmitted to the shelf. Good luck. I really recommend a wall shelf. It makes analog a lot more pleasant when you have springy floors.
Springs or sorbothane can both be brilliant at isolating the turntable from resonances but only within a fairly narrow movement/frequency band. Project and Roksan have both successfully used sorbothane/rubber decoupling for years but neither would work well if the they were used in a car, on a ship, or a plane. You really need to first look at what your turntable is sitting on. In turntable terms it’s probably wobbling like crazy.

As chayro said it’s unlikely any deck can withstand springy floors so a carefully located wall shelf (walls resonate too) may well be the best option. Alternatively, you could try to isolate the table that the deck itself is sitting on.

The good news is that whatever method you chose - tracking performance and hence sound quality - will improve.

I know some people with HW-19's took out the springs and used sorbothane/rubber in its place
I made a video some times ago.https://www.youtube.com/watch?v=mcoBxztdA1sFrom 0:40sec. you can see some measurements with Sylomer.
Sorbothane is not long-therm stable.
One possible issue with any turntable springs is that they aren’t the correct spring rate to be able to handle the extremely low frequency of the seismic vibration. It’s neceassary to get the total Fr down to say, 2 or 3 Hz, ideally, before very good performance kicks in. Alternatively, you can load the existing springs with a heavy slab of granite to reduce Fr.
You might try what was used to good effect in the final iteration of the TNT turntables, that is, squash balls. At each corner a properly sized piece of wood with a central indent on top (such as you can make with a large counter-sink, a spade bit or a forstner) can hold the ball in place with the TT on top of it. Adding something heavy underneath can complete the base: a sandbox, a thick butcher block, a piece of granite or marble.

Owners of the HW-19 VPI's also use the SIMS Navcom Silencers in place of the stock springs, but they are no longer in production. However, Navcom products are still being made for other purposes, particularly firearms. Others use roller bearings (by Symposium Acoustics or Ingress Engineering), Herbies Tenderfoot, and what I am intending to get---Townshend Audio Seismic Pods, an advanced spring-inside-a-bellows isolation device.

As others have mentioned, the spring and mass system has to be properly designed for it to effectively isolate. I still have an old VPI HW19 (original, not a later Mk X or Jr. version) in a closet, that I never bothered to hook up. It uses springs, but the arrangement just seems all wrong - there’s just no way it’s going to be effective. Thank god I eventually purchased a SOTA Star III, and got into vinyl right. The SOTA’s spring suspension is properly designed, and extremely effective at isolating. You'll be hard pressed to find anything more effective without getting into fancy rack systems. 
I've been considering two types of systems for isolation - active and passive.  Active versions are microprocessor controlled isolation systems (Herzan) and passive versions are spring based (MinusK).

The active solution is one-size-fits-all.  The passive solution, you have to order the unit according to the weight you are isolating.
@james1969 I can certainly vouch for the benefits of active isolation systems but they are not compatible with all turntables. For example tables with very floppy springs like the Linn may end up fighting the isolation. The TS-150 works very well with my EAR DiscMaster which has very stiff springs. You might also consider the Taiko upgrades which are both attractive and sound improving 
@folkfreak I agree, you should not have competing isolation systems which will cancel each other out.
I designed a dual layer heavy mass-on-spring iso system somewhat based on the Super Duper isolation systems employed by LIGO in the experiment to observe gravity waves, the amplitude of which are on the order of an atomic nucleus. The trick is to sufficiently separate the Fr of the two mass-on-spring subsystems so they won’t interfere. Brad at Revelation Audio has the only Nirvana Dual Layer iso stand out there. The Nirvana employs extremely hard NASA grade ceramic cones to support both the stand itself and the component on the top shelf. Did I mention VERY heavy masses? Give me a stiff enough spring and I can isolate the world. 🌎