Turntable isolation platform Recommendations?


I currently have a Critical Mass isolation platform on loan. Does anyone have any other suggestions I might look at?  Possibly considering the HRS 

any feedback would be greatly appreciated..

iconicaudio
There are a lot of principles in common. Skyscrapers for example use almost the same damping system as is used for speakers. In both cases the idea is a mass damps resonant behavior. Springs don't damp at all but they do isolate allowing vibrations to be damped or dissipated within the component itself. This can result in some resonant behavior that colors the sound. Townshend adds a very specific small amount of damping to greatly reduce this resonant coloring of tone.  

Same thing happens even within the turntable. Part of the problem is isolation to prevent environmental vibrations from getting into the turntable. Another part is preventing vibrations generated within the turntable itself from getting into the environment, because this sets up ringing which smears and colors sounds even more. A third aspect is to dissipate vibrations generated within the component, essentially converting them into heat energy. All three need to be done, and as if that isn't hard enough they need to be done equally with frequencies across the audio band. Or the sound becomes colored. 

The crazy part is all these things don't just happen in turntables. They happen in everything. Even in speaker cables, vibration control is a factor.  
The best and most economical platform is a diy sandbox with whatever wood you want
just make sure to heat the sand in the oven before installation
Don't know what issue you are trying to resolve but after many tries with my system the one device that solved all the issues were the Solid-Tech feet of silence.  They're fairly economical too at $500 for 4 - at least when I ordered them. Put those babies underneath the feet of your table and be amazed.
Having owned both SRA and Critical Mass platforms nothing beats my Vibraplane.  I still loved my critical mass platforms and used them under my Joule Electa Destiny’s were they served me well.  I have owned the following tables, SME 30/2, kuzma xl4, TW AC3, micro Seiki rx1500fvg and a Transrotor Rondino.  All benefited from the vibraplane now in its 16th year in my system.
I have a Rockport Sirius 11 which weighs 200lbs would Critical Mass be the best platform for it ?