Testing the Yamamoto HS-4 Carbon Fiber headshell.

Noromance, I don't know why I did not bring it up earlier in this 2-year thread, but I completely agree with you on the "sound" of carbon fiber when it is used structurally in audio components, except for headshells.  I have not at all liked the Well Tempered tonearms, for the same reasons (and others) that you mention.  I heard the same dull, sluggish SQ from the Sonus Faber speakers that first came out with CF cabinetry.  Likewise, I do not much like the Black Diamond racing CF shelves or cones.  With the headshells, as I have said repeatedly, I think it has a lot to do with the compliance of the cartridge.  Low compliance cartridges put a lot more energy into the headshell than do high compliance ones.  Since two years ago, I now run my Koetsu Urushi in my FR64S tonearm/B60 base, using an Ortofon LH9000 headshell.  Formerly, I had the Urushi in my Kenwood L07J tonearm, which has much lighter effective mass, but also using the LH9000 headshell.  The Urushi is sounding better than I ever thought it could, in its current livery, which is to say better than in a CF headshell.  The LH9000 is a metal layered composite and weighs 18g by itself.  Anyway, for other than headshell construction, I hear what you hear with CF.

Chakster, I am not sure I get your point.  Who is it that confused the graphite Boston Audio record mat for the carbon fiber Yamamoto (or Oyaide, or etc) headshell?  In addition to my two Yamamoto CF headshells, I also own the Oyaide one, just to see for myself if there is any qualitative difference in their sound(s).  So far, no.  But Noromance does not like either the graphite mat nor the CF headshell, and he knows the difference. Bill Stevenson doesn't like the CF headshell either.  You, Halcro, and I do like the CF headshell.  Yet we all (Nandric and Bill included) own very different audio equipment. Go figure.
Nandric, Don't worry. I pay for our travel to Tokyo.  About once a year, for the past 3 years, we have been renting an apartment via Airbnb, for 2-3 weeks each time.  Before that, I used to stop in Tokyo on my way to and from scientific meetings in Thailand or Vietnam, to see our son for a day or two.

My secret is that I buy headshells in Tokyo where the prices are about 33% lower than eBay.

Nandric, I know that we both think clearly, at least.

Serbians are particularly acute, I hear.

Dear Noromance, By no means am I implying that you or your judgement are "wrong" or that I am "right". Your Garrard set-up is very analogous to my own modified Lenco set-up (idler-drive, slate plinth, massive after-market bearing). On the Lenco, I use a DV505 tonearm and on that tonearm I most often mount MM or MI cartridges. Those types do not put so much energy back into the headshell/arm wand, because of higher compliance. The Lenco also runs with a Boston Audio platter mat. (Your worst nightmare, apparently.) This set-up feeds the MM inputs of a Manley Steelhead, modified a bit, and the Manley drives the built-in direct-drive amplifiers of my Beveridge speakers plus an outboard woofer separately driven by a Threshold amplifier. I’ve also used the CF headshell on my Victor TT101 with SAECSS300 platter mat and a FR64S/B60 tonearm, also feeding usually the MC inputs of the Steelhead. It was Halcro who originally suggested to me the possible merits of the Yamamoto, and I am happy that he did. But I wouldn’t say the Yam "blows away" all other headshells; I would say that it is "good", at least a little better than the various metal headshells I have used on these systems and affords a certain solidity to the music, for want of a better word. I do think that the headshell needs to work well with the cartridge. Cartridges on the Lenco have included the Acutex LPM320, B&O MMC1, and Astatic MF2500, but also the MC type Audio Technica ART7. On the FR64S, it only recently got a second Yam headshell and right now I have the Dynavector 17D3 on that one. I think the 17D3 is the only cartridge I’ve used on the FR64S since installing the Yam headshell, but I also have run the AT ART7 and the Acutex on that tonearm. The FR64S has an inherently high enough effective mass that you can get away with a light-ish headshell, like the Yam and still be in the right range for resonant frequency with low compliance MCs. (But surprisingly, it sounded great also with the high compliance Acutex.) Like Chakster, I cannot hear much difference between the BA mats and the SAECSS300, except that both are better than anything else I’ve tried by a fair amount. Or to put it another way, there is a qualitative difference between these mats, but I like both. I don’t think or expect that one headshell would be best for all occasions; I use an Ortofon LH9000 (18g) on my Kenwood L07D with Koetsu Urushi, because I think the Urushi really sounds best with high effective mass, and the OEM L07D headshell is only about 10g. I hear a big improvement with the Ortofon. Oh yes, and the L07D sports a custom-made pure copper platter mat.
Could it be that you are liking a certain resonance in your system that the BA mat and/or the CF headshell is taking away or dulling? It could equally be that my own systems generate a certain resonance that needs squashing. Such is life.

noromance, Was it you and I who had a sharp disagreement about the Boston Audio Mat2?  If so, seems like your impression of the Yamamoto CF headshell and my own are equally at odds.  I've liked mine so much, I now own two of them, like hdm.  But obviously, we hear differently on different systems.  My systems are inherently highly detailed and seem to benefit from the very same treatments that you don't like so much.  I am also wondering whether the "sound" of the Yamamoto will be partly dependent upon the tonearm.  I am using mine on a FR64S with B60 base and on a Dynavector DV505, respectively.