David, looking fwds to your thoughts. This shouldn't become a belt v dd argument, ideally if poss just really comparing and contrasting pros and cons of belt/dd/idler/rim drives. There is a lot of YMMV and synergy in this and all audio, but maybe some common ground can be found.
For anyone reading these are mostly generalizations based on 3 Reference quality tables. A Reference product doesn't mean expensive, its one that has few weaknesses, is more or less neutral, correct, musical, capable of delivering enough harmonic and tonal contrast to resemble the real thing and doesn't embellish the sound. Equally important the component is of high enough quality to be used as an acceptable Reference to judge others of its type against it. I consider all 3 as Reference level and equal, acceptable representative of each technology. I'll be specific with the tables to give you better context.
Belt- Micro Seiki RX-1500 with gun metal platter
Idler- Garrard 401 in a custom plinth
DD- Technics SP-1000 mk3
I had SME 3012 arms on the Micro and the Garrard, Technics had the SME 3010. Cartridges were Ortofon SPU & Denon SL1.
Reference level Idlers that I've heard from the Garrard 401 all the way to the EMT 927 share similar qualities. The scale of sound is big, images are solid and PRaT is excellent. Musicality 2nd to none and very "Natural".
In comparison to the Garrard, the RX-1500 while equally musical and natural has a different presentation and PRaT. The sound lacks the body, solidity and scale of the idler but is more nuanced, specially in the lower frequencies. More importantly is almost as "Natural".
The SP-1000 mk3 is a superior built and engineered product than the other two. Sound is very detail but a little cooler (not wrong) than the other two, specially compared to the Garrard. What I can't get past is the Servo Controller unit which is in the DNA of direct drives. I find the continuos adjustment of the Servo Controller very intrusive affecting P & R (Pitch/Pace & Rhythm). Because of the Servo I find that DD table fails in the "Natural" department. I have to add that I find the presence of servo bothersome even in belt drives.
Take my comments as you wish but recognize that we can have different preferences, priorities and sensitivities. Also the degrees that these qualities manifest themselves is system and setup dependent.
david