Micro SX-8000 II or SZ-1

Kipdent, i have the same impression when I tested the flywheel on my Micro - the sound improved. But maybe I hear this only because it should serve me as the owner... as FM login states. So what.

Fm_login, sorry, but I am way past that period in my life when I was young and angry enough to react to a comment as sophisticated and throughout displaying deep audiophile and mechanic insight as yours.
Sorry that basic vector geometry is BS to you.
But that is certainly not mine nor Micro Seiki's problem.

Dertonarm, I passed the period in my life when I was trying to educate people. You stopped react because you lost your anger, I stopped to educate when it not worth it because I got wisdom and experience to deal with currently angry or formally angry audio people. I shared the facts, now to interpret them it is totally up you and others who have interest Micros. I would be worth to mention that I shared them not because my desire to argue with you or because my interest to educate you but rather to prevent you and you-like to spread disinformation and urban legends. If you have no sonic or mechanical insight on the subject then you probably shall not make the statements where you put yourself in a position of being a faulty authority on the subject.

Radicalsteve, applying a damping material inside the platter does not work, I have tried it. Using different TT mats do work very fine, try a sorbothane mat atop the Micro with a layer of very hard rubber atop of sorbothane. I can’t give you specific as too many variables involved but even a basic hard rubber later atop 5000 will do very fine. The 5000 is very simple and extremely good performing TT as is. People invent the false differences about turntables presuming that many logical concussion about TT design leads to sonic differences. In reality the methodologically properly to evaluate the differences in sound between two turntables is a quite complicated task… Anyhow, to ask for intellectual honesty and rational sense is mostly too much to ask from audio people.

What is here disputed about the Micro Seiki skeleton TT's was already done so widely and brought to conclusion by the later 1980ies.
Micro Seiki introduced the Hs-20 and HS-80 to further improve the performance of the RX-1500, RX-3000, RX-5000 and SX-8000.
This enhancement in performance was founded on increased inertia and decreased noise and wear in the lateral bearing because - proper applied and aligned (no problem at all - belt or string, you just need balanced distance, equal length or a decent spring-tension-gauge) - the lateral bearing is force free.
This - BTW - works on most if not all (direct TT's are an obvious exclusion and Idler-wheel-drive needs some different treatment) TT's, as it is a simple mechanic principle of force vectors eliminating each other.
Each and every bearing with a shaft - i.e. with a lateral bearing - being addressed by a string pulling towards the motor in order to apply any tension on the medium (string, belt, tape) spinning the platter will benefit from the elimination of that one-side force.
Lesser noise - lesser friction - lesser wear.
Its obvious - a simple sketch on a sheet of paper does illustrate the point and principle very nicely.
The dampening of the "bell-platter" of the big Micro Seki's was addressed by Micro Seiki's copper-mat and in the early 1980ies by several soft and hard platter mats introduced by japanese manufacturers to better or lesser results.
I have too seen Micro platters damped inside (not easy done with good mechanical results, as the coating has to be done very precisely and homogenous so to not ruining the inertia force of the platter) with very good results, but these were all further damped with acrylic-mats (glued to the platter...) on top of the platter.
The improvements with inertia units by Micro Seiki or custom made devices are sonically apparent to all audiophiles who care, whose set-up is capable to show it and whose hearing isn't deafened by dogmatic prejudice.
This - for once in our audiophile world of often nebulous results and experiences - is fully backed up by applied science and simple mechanical laws found in every middle high-school physics book.

And yes, - I have used the RX-5000 too and am currently using a highly modified RX-Micro Seiki ( 4 inch double platter with isolated spindle (no contact to bearing) and 38 lbs highly dampened platter - gun-metal and PVC) and will soon incorporate an inertia unit similar to the HS-80.