I suspect a lot boils down to plinth design etc, and both are clearly good decks, but it took me less than a track to decide I vastly preferred my TD-124 to an SL1200G! The old idlers will never compete on silence, but they get the music out.
FWIW I think a lot of this comes down to mass and/or the lack of it. I suspect I didn’t like the Technics I tried because it was over-damped and stored energy. There is a very interesting breadth of opinion in turntable design spanning everything from gigantic high-mass belt-drives at one end through to the lightest possible high-end Regas at the other.
As such I’m inclined to think mass plays as much of a part as drive system, at least between DD and idler (both of which being rock-solid and high-torque). The SL1200G is far, far heavier and more damped than my TD-124 in its lightweight plinth, though the 124 has the heavier platter at about 5kg (mine is the iron type).
On instinct I’d pick a good 401 over an SP10 as I know very well I enjoy Garrards having owned a 301. For me it is a very safe and proven choice, though in hindsight after playing around with slate I’d revert to a plywood top-plate and squash ball/rubber decoupling in a Lorricraft style rather than high-mass. I’m pretty sure I traded some ‘fun’ for ‘quietness’ moving to slate. To be honest I don’t think I like high-mass anywhere in an audio system, be it turntables or speakers. I still think you need a fairly chunky platter for that real rock-solid gravitas, but the Garrard, Lenco, or cast iron 124 platter is enough, no need to go further, and I suspect losing mass elsewhere is likely beneficial.
