This isn't a response as such to the original question but this thread like so many others ha evolved somewhat in an interesting direction and i'd just like to add something.
I bought a SME 20/2 last year at the end of the run of the Mark 2 which came with the charcoal coloured platter. I bought it without an arm as i had a SME IV arm that i'd been using on a SME Model 10 that i was going to use on the 20 and put another arm on the 10 which i'd kept for a second system. The cartridge was an Ortofon Cadenza Black. Over 6 months or so, as much as i liked the Model 20 i felt there was something holding it back but i couldn't put my finger on it. The Cadenza Black just wasn't giving me the excitement that an Ortofon Jubilee was when that was on the same arm but on the Model 10 turntable.
A new Ortofon AS212S tonearm came up for auction on Ebay so on a whim i bought it and ended up with it at half retail. Mounted on the Model 20 with the Cadenza Black hanging off the end it is a stunning combination with more detail, wider and deeper soundstage and all the usual audiophile cliches, but most of all is so much fun. I've never doubted the qualities of the IV arm but there is something in the synergy between cartridge and tonearm that makes all the difference.
Now if SME would put their skills to building a cartridge.............:>)