Looking for the best moving coil cart that is around $5K used

I'll weigh in with a few terse comments:

1. Setup is  the weak link in the vast majority of turntables/Tonearms/cart.
2. As used cartridge is an unknown, and at best has only a portion of its life left - not just the tip, the suspension
3. I have not had that Pioneer, bu if its up to the challenge that you must pose with a $5k cart, its a bloody miracle.  See setup above.
4. Note that TTs are primarily about reducing motor noise and speed variation; tonearms however are more than good/bad - the mass-to-cartridge compliance matching becomes critical - just liek springs and dampers on a race car.

Handyman-

I want to comment on the speed/DD/strobe thing.

I don't know how much technical knowledge you have about turntables and analog sound playback, but a strobe tells you very, very little.  Its not speed accuracy that we need, it is consistency and absence of noise.

Its the small, maybe tiny, higher frequency changes to rotation speed that create distortion, combined with all sorts of vibrations. Think about this:  the vibrations mix with tiny groove wall ridges. How does your cartridge tell one from another? Answer: it cannot. It reproduces the music plus the vibrations = distortion.  Similarly a small difference from the proper 33 1/3 rpm speed is generally inaudible except to those with perfect pitch.  Since we can tune to any note we like, even with perfect pitch speed accuracy is largely over rated. But CHANGES in speed create wow and flutter.  I doubt your table wows (low frequency changes), but since it is a direct drive, with nothing to absorb the imperfect drive of the AC motor, it WILL flutter.  This creates distortions that are easily audible and generally not harmonically correlated - they are generally multiples of 60 hz.

A suspended table filters out vibrations.  A belt filters out motor vibrations> a heavy latter is a flywheel - used n pretty much everything that demands true speed consistency (not accuracy, consistency - its OK if it is consistently off by 0.1%)

Maybe the Pioneer sounds great. I cannot say.  They may have the worlds quietest motor and the worlds deadest plinth - really, they may.  But your technical argument is worse than weak, its just dead wrong.  Remember - the $5000 cart you are willing to buy still, debate aside, tell the difference between a groove and a vibration from a motor or the room.  Filter them out. And for heavens sake match the cartridge compliance to the tonearm mass, and get VTA right - those are free!

G