Thinking about this after some sleep and waking up in a better mood, I don't think we're all in as much disagreement as it seems. What makes a good turntable? We all seem to be saying that its accurate speed, low noise floor, and resonance control. I think where we differ is in how accurately the specs show what's going on with those problems.
A lot of modern turntables (and some very nice vintage ones, even DD...I'm speaking of the likes of the Kenwood L-07 as an example, or the Yamaha GT-2000, or Sony PS-x9) go to extreme lengths to solve these problems BEYOND what looks acceptable on the spec sheet. And to many listeners, its readily apparent that it makes a difference. This isn't an argument of new vs. old, its an argument for overbuilding and over-solving the problems that already look to be solved by specs (when they actually aren't IMHO).
The SL-1200 is very accurate for speed when measured according to the specs, and also in general when listening. Is it enough? Well, look at the GT-2000. It is DD, but the engineers didn't think that was enough. It also has a massive platter, which would help in resonance control and also give a flywheel affect, which would help power through transients and add an immediacy to the sound (the kind of thing the idler fans speak of, and which I found the Empires to also have). Like it or not, the Quartz lock isn't fast enough to react to a transient. You simply have to not slow down for it to sound 'fast', and that means either the torque of an idler or a very big platter with momentum behind it. There's no spec for that, but its a very simple thing to solve..but not simple to solve cheaply. Gigantic machined platters are not cheap, and they are not found on the average consumer grade turntable. If you look at the AR-xa, the platter really isn't that substantial. Follow the design through the TD-150, Ariston and Linn Sondek and you'll notice the platter gets bigger. That isn't on some whim of the design team. That's speed stability being handled outside of the average of the RPM spec.
Vibration and resonance control are also among the things that makes a great turntable. If you look at a lot of modern turntables, the motor is only attached to the platter via the belt (and the surface they sit on). That's a very simple, non-voodoo way, to solve a problem. But it adds another...now the motor is loose from the platter. The more expensive way to solve this is to make the motor housing much heavier and bigger, so it doesn't move in relation to the platter. The bigger the platter, the bigger the motor, and the bigger the housing, and the bigger the cost. My Marantz TT-15si has a separate motor, and my big gripe about that turntable is the motor housing is too small and too light. It can move in relation to the platter, and torgue and speed suffer. So why do I run this table instead of the SL-1210? Because the other solutions that make a great table are handled better in the marantz. The entire thing is anti-resonant, its made of acrylic. The arm is exceptionally well made, and tracks better than the arm on the 1200. It also is lighter and supports the carts I want to run on that table, and to my ears the main bearing is more quiet..the table has an overal 'blacker' background to the sound than the 1200. Do these things show up in the specs? Not really.
It's no accident that the most highly regarded turntables through the history of the format are beasts. Even the SL-1200 is pretty heavy. It's good enough for a lot of people, and its good enough for the specs. But engineers didn't stop there and I'm glad they didn't. I'd love to own one of those old giant DD beasts, for what its worth. A friend has an L-07 but still thinks his Sota Sapphire sounds better, for what its worth. I almost guarantee the L-07 has better specs..but the hobby is about listening, and that's where a lot of us make the call.
