Question about Corsair HX750i

AX series (most expensive) is 80 plus platinum certified
HX and RM series are 80 plus gold certified,
corsair are very quiet i build my own computer case so i need a very silent psu.
ax are build by seasonic, they are very good gaming psu, the hx series are build by cwt, corsair does not build psu. all i series can be monitored via usb cable so u have more control of u power in u pc if u consider to oc.