it doesn't look much different then other brands to me
Shanling m9+ ( powerbeast and ultrarefined , stageing , tilted analogue ) is like a shadow still
a&k sp3000 ( definitely didn't attract worldwide follow , while sp2000/ti/cu gathered it more-so and in the long run )
Fiio m15s ( another powebeast and linearly refined , nearly on par with m17 ) in the shadows or so still
it's true also that lately technology and refinement on portable scales up sooner and faster then in the past , so products overlap one eachother ( think iems .. but daps are in a similar mood )
I think its the price mostly.
Shanling M9+ uses Stock, Off-the-shelve Hardware for 2700€... thats a tough price.
A&K SP3000 does the exact same thing and sells for 4300€
Those are very very tough prices, even outpricing Sony.
If you are more expensive than the "original" who invented the product, but then use nothing exclusive or special that sets apart your product from an 650€ M11 Plus ESS, why should people buy it?
If Sony would stop making DAP tomorrow, completely quit production, i would buy an M11 Plus ESS and just use that. What you get with the Walkman, you can not get from any other company that exists. What you get from Shanling and A&K, you can get from almost every Chinese company that makes DAP.
Sure, you can cash in on the die hard audiophile but mostly these products are invented (and marketed) not for audiophiles but rich people who want to have it for the sake of having it. So of course they are not talked about that much because nobody owns them. Or the people who own it are not active here because most of them live in China and Japan.
A&K marketed the SP3000 not for its insane sound quality, but for using the same materials that are used in watches. When you DAP markets that he uses the same material than watches, the target group is clear imho
Sony: "We use copper to reduce the output impedance, look at our self developed capacitors and our self develop lead to give our self developed full digital amp the best sound quality possible with these giant LCs"
A&K: "We use an material that is shiny and looks good and is durable and also used in watches. Inside you find chips that cost 30$ on the open market but because we put them on an PCB, they are better. You don't believe us? Better do. If you pay 700$ extra, we coat it even in gold for you! The sound? I don't know, doesn't change, but look how shiny it is"