Well I think that the forum silence here is mainly due to the fact that we have little or no experience of the Technics SL-1210 range... There reputation is less built upon their 'audiophile' credentials and more on their reliability and durability for club deejays, the basic theory goes that comparing a Technics SL-1210 to a Pro-ject 6 is like comparing an articulated lorry to a sports car. One is designed to deliver time after time over a club PA where the finer elements of the music is lost to pure sonic volume... the other has been tweaked around in order to achieve the maximum output it can... this can be reflected in the secondhand price (I do not do new...) where a Technics can be picked up for £150 and the Pro-ject is worth twice, maybe thrice, as much...
.... now, how much of this is fair? How much is merely audiophile snobbery...? I do not know. Hopefully not much else what are we all bothering for? However I suspect that this is why there is scant replies to this question... should anyone know then I, too, would love to hear the answer.