Seasonic revamped their already excellent G-550 unit to offer a new version which, with a few small changes, offers higher efficiency at low loads and an increased hold-up time despite its smaller bulk cap. However, the older G-550 scores a slightly higher performance due to its tighter voltage regulation and better ripple suppression on the minor rails. That said, its successor is a great PSU that simply hammers the competition in its price range with its great price/performance ratio. While I reviewed the first G-550, its price was almost 100 bucks, so it wasn't as affordable, but you can find the older unit for roughly 20 bucks less now, which is a significant price reduction that makes it a good investment for anyone in need of a top-notch PSU for a mainstream or mid-level system. The new G-550 Seasonic unfortunately doesn't come with an additional pair of PCIe connectors, which would significantly increase its usability. Seasonic was probably afraid someone would try to feed two high-end VGAs, which could have caused havoc. I must also note that this revision is officially Haswell ready, although the older G-550 has no problem whatsoever with Haswell sleep states since it exploits DC-DC converters to generate the minor rails. Lots of fuss lately with Haswell ready PSUs. Also keep in mind that anything group-regulated will most likely not meet Intel's Haswell requirements, while any PSU that uses DC-DC converters will easily do. An easy way to figure out if a PSU uses DC-DC converters is by determining whether the +12V rail can deliver the unit's full power or very close to it on its own.

To sum up, the fresh G-550 is another excellent PSU by Seasonic and one that currently sells at a very good price, so don't hesitate to buy one if you need a mid-capacity PSU and can afford the G-550. Not only does it offer good performance while operating reliably, it is also backed by a five year warranty. I expect Seasonic to provide four PCIe connectors with the next revision so I can finally stop complaining about the lack of VGAs I can connect to this PSU.