techPowerUp posted a review on the Seasonic G Series 550 W

Such hard times demand a good understanding of the market, and Seasonic apparently hit a jackpot with their new G series that consists of budget oriented PSUs promising high performance and efficiency with a five year warranty. The fresh G series consists of four members with capacities ranging from 360 W to 650 W. All feature Gold capacity, a single +12V rail, ball-bearing fans, and high-temperature-rating electrolytic capacitors. All are based on modern platforms. Every G series PSU, with the exception of the smallest one, also utilizes a semi-modular cabling design with flat modular cables.

It is, without any doubt, very nice to see top-notch OEMs like Seasonic offering higher-end platforms for user-friendly prices. The capacities of the G series units may look low to some users, but hardly any system actually needs more than a 500-600W PSU. Just take a look at the power consumption page of one of W1zzard's reviews and check how much power a modern graphics card, without any doubt the most energy consuming component in a system, eats. That is, if you think a system actually requires a stronger PSU.

"The stronger, the better" rule doesn't really apply to PSUs. The best option is to get a PSU strong enough to handle your system's power consumption. That way you will have the best possible efficiency at typical loads. Besides, the money you will save on electricity will also protect the environment by lowering your energy consumption and carbon footprint. It is better to get yourself a low to middle capacity PSU that matches your system if you are not a hard-core overclocker with three to four graphics cards under the hood.

  Seasonic G Series 550 W Review