Anyone heard/compared these carts?

These are not exactly comparable cartridges... and I don't know if you're looking for something specific?
I would find the Allaerts the most musically precise (tonal accuracy, relative dynamics, good extension maybe a tad on the light side).
To coin a phrase (or two): The Koetsu has the unique ability to pick up what it can give you beautifully and disregards the rest. Hence, you don't bother about that rest.

I haven't heard the Sumiko in familiar surroundings.
Cheers

Urushi had more detail -- extension if you will. Rosewood sig was more "romantic" (possibly attributable to more pronounced mids?)
Unfortunately I don't know your Dynavector to compare. Cheers

Hi Cmk -- No, I can't bring myself to say the Koetsu is "coloured" because it is very "magically musical" as extremephono put it... So, is it musical truth??
I don't know, but I can sit back & enjoy myself listening to a big Koetsu w/out bothering about details that may be missing.

An Insider or a Colibri (to choose models not on your list) reproduce more of what is on the LP (i.e., the recording -- however close or far away that may be from the actual musical event being reproduced). So "closer" to the recording...

BTW, you understand that this is a very personal take. I am very familiar with the products but, at least, there's no "pride of ownership" affecting what I say :)!