The SP 10 is 0.015%. If you think you can hear the difference then you need to take Michael Fremer's place on the staff of Stereophile.@mijostyn Certainly you don't hear that in terms of pitch. But as the machine speeds up and slows down, it causes the arm to exert variable tracking pressures on the left and right sides of the grooves due to variable skating forces. This creates a bit of a 'shimmer' in the sound stage. To hear what this is about, sometimes its useful to compare the LP to the same title on tape. There is a 'locked in' quality about the soundstage with better speed regulation- its more palpable.
BTW I agree that the arm is one of the weaknesses of the Technics, but its a lot better arm than was on the old SL1200s (it has superior arm tube material, better bearings and the bearings have no slop in them at all); not bad when you consider the price. But I've installed the Triplanar arm on a number of the new SL1200s and the difference is pretty remarkable. Seriously if you've not heard one in person, its an entirely new machine from the ground up, having only appearance and the fact that its a turntable in common with the older SL1200s; I've not heard a belt drive that can keep up.