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

Ditch the Pioneer and get the VPI tuned up and listen to it with your Koetsu. If you still can't tell the difference, I'd give up on analogue as you aren't getting your money's worth.

I say that as an Urushi (not 'Urishi') owner. It deserves a well set up deck and an excellent phono stage like you have - but not on an inappropriate arm on a far less than stellar player..

I am very happy with Lyra Etna SL

Well you didn't ask me however I always have an opinion, one that at least with my kids goes un heeded. So. Audition a good phono stage in your system, I would guess you can now tell the difference between the VPI and the Pioneer. 

You are limited by the tt arms you have since I’m guessing the vpi has the jmw9 tonearm. If you go with an upgraded cartridge up to $5k, you need to upgrade the tonearm, maybe using the vpi tt with a new vpi 3D arm, 10” or 12” if they would fit. I would also disagree with you on the comment that your tt’s sound the same or not the weak link.

I truly love this forum. About the time I start thinking I know a little concerning high fidelity, I find out how little I actually know. I will admit, sometimes my opinion is clouded by an adult beverage or two, but still think I have a discerning ear. Although it's unlikely, I will get any takers, I live in the Nashville Tn area and am sending out a standing invitation to anyone wanting to stop by to explain to me, what I'm not hearing. Maybe I spent too many years at ZZ Top concerts, where even if u were on the last row, the sound was literally ear splitting. Yes-I'm an older guy and as I have mentioned, can't hear much above 12Khz. Perhaps what I'm missing, is in this higher range??  I've been into sound since I was four and went to my uncles and. saw where he had disassembled my grandparents hi-fi and placed the two speakers in different parts of the room. I went home and took my small tubed record player apart and took out the 4" speaker and have been intrigued by sound ever since. No such thing as stereo back then, or it was a fairly new thing. Anyway, guess my ears are old-maybe too old to hear the difference. According to my RTA, I have a pretty good room response.  I'm not ready for the old folks home just yet🙂