Looking for a New Cartridge

Koetsu are fantastic on the right arm. It’s a shame to be limited to the VPI unipivot once you reach the level of cartridges you’ve got. But the Orotofon Cadenzas are great cartridges and I’ve heard VPI likes them on their tables. I've got a Bronze and I wouldn't call it too warm overall, just relative to the other upper-line Ortofons I've heard.

I didn't like the Soundsmith cart on my VPI table.  Yes, it was a good match compliance wise, but just didn't like the dry sound.  I have owned the Ortofon Quintet Black and Kiseki on my VPI, and also know the Cadenzra series well. If you like the Quintet sound, I would stay with the Cadenza series or look more into the Airtight PC-7.  I hear the Airtight PC7 is a great value at the price point as well.  

I’m not an expert but any means... 
but I have had these on my Mac MT-5.
Blue Point No 2
Soundsmith the Voice and Paua
ortofon 2M Black mc
dynavector 20x2 
london decca super cold
and clearaudio concerto v2

the clear audio killed them all on my arm and table.
Easier to setup. Never mistracks, very tolerant and great overall sound. Love it. Will get it again or one step up next time.
Same as you the 2M Black was a “transition” cartridge that was really awesome too.
Ryan

It seems to me there may be a much better way of looking at this. You already have a known top-flight cartridge. Why waste time chasing down the few cartridges that might work well with your arm? It seems to me the arm is the weak link. Always improve the weakest link is my approach. For the same money you are looking at spending on maybe the right cartridge you can buy an Origin Live arm that will make not only your Koetsu sing, but anything you put on it.

Origin Live are a breeze to set up. They come with a great interconnect hardwired, eliminating connections and the expense and hassle of matching cables. That's what I did, and my Conqueror is so much better than the Graham it replaced its not even funny- despite the Graham running some very expensive interconnects custom made for me by Ted Denney!! I seriously doubt you will run into any cartridge incompatibility problems with any Origin Live arm.

I have the Prime Signature with the Cadenza Bronze base on VPI’s recommended cartridges for it, and the sound is fantastic.  I do not see why you would be disappointed with the Cadenza Black, but wonder why VPI did not recommend it over the Bronze.  Possibly about the same performance for a good bit more money??  You might want to contact VPI directly, and get their input.