I can give you a little of my perspective in that I have been running Koetsus, am very familiar with Kuzma's products but cannot comment on other aspects. I have been running two different new fresh authorized stone bodies on Kuzma's original Airline arm (which has a similar, locking VTA tower off axis of pivot point or in the case of the Airline, the remaining body of the arm and rail on which the air bearing travels). Both of these cartridges use the platinum magnets and I was told by someone who has one stone body and a Rosewood Platinum (whatever it is called) that the latter performs in the same league as the stone bodies. I don't know about the lower priced versions of the Rosewood, though I certainly remember the original that came to the U.S.
The stone bodies present a rich, full bodied sound with amazing bass (linear arms are not noted for bass) that is full of character if it is on the source material,, e.g. a double bass solo, drums- I listen to a lot of post-bop small combo.
I did try one of the Koetsus on a 9 inch 4 Point, an arm I like very much (though much stripped down from the longer versions), and did not like how it sounded-- perhaps it needed more adjustment, but that cartridge sounded beautiful out of the box on the linear arm.
Oh, I had a Steelhead-- so that was one other thing we shared at one point. Good luck. My experience with Koetsu has been very positive- not the old technicolor midrange and roll off of the originals.
The stone bodies present a rich, full bodied sound with amazing bass (linear arms are not noted for bass) that is full of character if it is on the source material,, e.g. a double bass solo, drums- I listen to a lot of post-bop small combo.
I did try one of the Koetsus on a 9 inch 4 Point, an arm I like very much (though much stripped down from the longer versions), and did not like how it sounded-- perhaps it needed more adjustment, but that cartridge sounded beautiful out of the box on the linear arm.
Oh, I had a Steelhead-- so that was one other thing we shared at one point. Good luck. My experience with Koetsu has been very positive- not the old technicolor midrange and roll off of the originals.