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.
Actually, if you search "silverstone psu buzz" on google, you'll get more hits than searching "seasonic psu buzz"...
And what on earth is a "kingwing", with a name like that I wouldn't trust any power supply they make.
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