SP10 Mk II vs Mk III


A couple of guys here were planning to do listening comparisons of the Technics SP10 Mk II vs the Mk III, in their own homes and systems. Has anyone actually completed such a comparison? I am wondering whether the "upgrade" to the Mk III is actually worth it in terms of audible differences between the two tables. Possibly mounting either table in a well done wooden or slate plinth mitigates any sonic differences that would otherwise be heard. I am thinking of Albert Porter and Mike Lavigne in particular, who were going to do the comparison. Thanks for any response.
lewm
Robyatt, What cartridges work well in the RS-A1? I've got one too, largely because it is so easy to move between tts, it will facilitate my ability to compare one tt to another. But the darn thing is so unorthodox in construction and implementation that it is difficult to know what cartridge to use with it, except by experimentation perhaps. For example, what is the effective mass of that crazy arm tube with the swinging counter-weight? (It's a rhetorical question, unless 47 Labs have given the into in the manual, which I don't have.) I heard it sound great on a Lenco with a simple Pickering MM.
Anybody aware of the SAEC SBX-7 plinth for the SP-10 mkII? http://yasshin.hp.infoseek.co.jp/saecsbx7.htm

Atmasphere, you've got a point though. Lead is not optimal - its got high mass but is 'unstable'.

I would rather go for a fiber-loaded (incl aggregates) compound that is pour-cast and then CNCd.
What do the SP10 experts think of this Teak plinth for sale on ebay??

http://cgi.ebay.com.au/Teak-Plinth-for-Technics-SP-10-SP-10MK2-SL-1000_W0QQitemZ390014496088QQcmdZViewItemQQptZTurntables?hash=item390014496088&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318
After lead now we have tropical wood endegered species ! I am not Greenpeace militant, but if we can chose between eco-friendly or not why not choose eco.
It will just add some proudness in our small niche hobby. No offence here, just a friendly reminder.