Magnetic (no wear), direct drive (low slip) mechanism.
High torque (1.5 kgf·cm or 0.15 N·m), which means the platter will spin at the desired speed almost immediately (0.7 s to reach 33 ¹?? RPM from standstill), and will very rapidly reacquire the desired speed, without "overshooting", if the platter is dragged or nudged. This aids beatmatching.
Very low wow and flutter (0.01%), which means that the platter will stay within 1/100 of 1% of the desired speed.
Heavy base (12.5 kg), and increased isolation of platter from base, reducing the likelihood of feedback or stylus jumping.
Variable pitch control, allowing the rotational speed to be adjusted from -8% to +8% (for the purpose of beatmatching).
High reliability: many examples of SL-1200s lasting well over 15 years of heavy use and withstanding physical shock without functional impairment.