The new Silverstone 500W ST50NF Fanless power supply is available now:
http://www.newegg.com/Product/Product.a ... 6817256075

Finally, an alternative to the fanless Seasonic X power supplies.

Someone buy it and tell us whether it buzzes/squeals/chirps like the Seasonic X fanless power supplies.
(I would do it but newegg doesn't ship to my country)

That's a pointless PSU, especially when compared against SS X or KingWing etc.

It's only bronze, it's not modular, it's way more expensive than SS or KW or just about any Gold PSU (not counting 1 kW pointless beasts, too). It's only as strong as SS X 460W - I mean 12V.

So far I fail to see a single reason to buy it

There is a damn good reason to buy it, and that's to potentially avoid the electrical buzzing noise that the Seasonics all emit. I'd settle for slightly less efficiency and slightly more cost if it means having a pure completely silent PSU. Just search Seasonic and buzz on the internet, you'll see lots of people complaining about how noisy the Seasonics are, even their fanless models. I personally have tried 2 Seasonic X 460's and they buzzed.

And what on earth is a "kingwing", with a name like that I wouldn't trust any power supply they make.

The single biggest deterrent to purchase is price: At $200, the 80+ Silver ST50NF is by far the priciest fanless PSU at Newegg. The $150 460W X460 and $160 500W Kingwin (made by Superflower) are both more energy efficient and have detachable cables. As for the buzzing X series complaints, I've had several 460s and 400s here, and I don't hear enough of it to think it's serious. Like all PSUs, get close enough & you can hear some, but it's a trace amount that is inaudible in a real system running in a real room.

(Aside: It seems to me that a problem with selling, marketing or even reviewing "silent" products is that so many obsessive-compulsive geeks want to prove you wrong, and they do everything they can to evoke some noise from the gear, never mind how. Hear a trace something or other which would go completely unnoticed in another product and they claim the sky is falling. )

Actually, if you search "silverstone psu buzz" on google, you'll get more hits than searching "seasonic psu buzz"...

It has great reviews all over the web, including here on spcr, I don't see any reason why not to trust them.
If someone wants to spend $200 on a psu with poor efficency and poor specs compared to the competition, there is nothing stopping them...
+1 to what Mike said