Bit-Tech published a review of Corsair's VX550W power supply

Continually, we find ourselves looking at great Corsair PSUs -- the HX, the TX and now the VX have all performed fantastically. The VX550W does exactly what it says on the tin and even though our model dropped a fraction below 80 percent load under significant 3.3V and 5V stress, it's very unlikely they'll ever hit these sorts of values in a real PC. Where it matters the Corsair VX550W works exceptionally well, hitting upwards of 85 percent efficiency throughout the rest of the tests.

We'd be torn between the significant benefits of buying modular, versus the extra cost and slightly lower power. I used the VX550W in my own home theatre PC for a few months prior to this review and it was nothing but fantastic. In this instance, cable management didn't matter since there was a large enough case that was designed just to be super-low noise: in that respect it worked perfectly. I even had to install an extra cathode it to tell if the system was on or off, simply because it was //that quiet I couldn't hear it unless my head was all of two inches away.

I had to swap it out for the Thermaltake Toughpower Q-Fan 650W we reviewed before the Corsair and while that quotes just 17dB you'd be very hard pushed to tell them apart. I'd still prefer to use the Corsair VX550W simply because the cables are better designed (4+4-pin EPS 12V instead of an 8-pin with a 4-pin tail), even though it's not modular.

For any Intel P35/P45 or AMD 770X, 780G based PC with mainstream components the VX550W should absolutely suffice, but it's not //the answer for everyone -- there are a lot more ifs and buts than when we looked at the TX750W. If you do decide to buy a VX550W though, you won't be disappointed.

Corsair VX550W PSU Review