Amethyst versus Nagaoka MP-150/MP-200


Does anyone have any experience with these two carts, by any chance?  I have the Amethyst and I've used it for about 40 to 50 hours now. I think it's a beautiful cartridge, and I'm a fan of Sumiko in general, but it doesn't hit the spot like some of the other carts I've used.  So I think I'm going to sell it and buy something else.  I've had my eye on the MP-150 for a while.  Would be curious to hear folks' thoughts on this cart, especially from anyone who has heard the Amethyst, too.  (Also, if anyone has thoughts on what a good selling price for the Amethyst would be, please let me know.)  Cheers.
three_paws
What is Amethyst? 
Look for Garrott Brothers cartridges, much better than Nagaoka
It's a Sumiko MM cartridge.  Sells for $600 in the US, and about $900 in Japan.

What makes Garrott Brothers carts so much better?  Thanks.
What spot does it not hit?
Nags are great but may lack top end sparkle—if that's what you're missing. If so, Audio Technica VM750SH or 760SLC will do the job.