SilverStone has a large number of PSU lines in its portfolio, covering every possible need in this market. Its entry-level line is called "Essential" and currently consists of 23 members with efficiency ratings ranging from the plain 80 PLUS certification up to 80 PLUS Gold. None of those units is certified, so far at least, by Cybenetics, so besides a more detailed efficiency/performance picture, we also don't have any information on their noise output.
The latest additions in the Essential line are three semi-modular units--ET550-HG, ET650-HG, and ET750-HG. As their model numbers show, those units cover the 550W-750W capacity range. They are also 80 PLUS Gold certified, have normal dimensions (16cm depth), and are cooled down by a 140mm fan which, according to SilverStone, offers quite silent operation. Those units will be available in the European market shortly (after January 17), and their MSRPs are 90€, 80€, and 71.5€ for the ET750-HG, ET650-HG, and ET550-HG, respectively.
According to our sources, the first shipment of those units has just arrived in the U.S., so you should expect to see them on the store shelves within the next couple of weeks. The MSRPs for the U.S. market, from the strongest to the lowest capacity model, are $95, $85, and $75, respectively.
The maker of the ETx550-HG units is Channel Well Technology (CWT), which is among the best PSU OEMs nowadays. We cannot know the exact platform that SilverStone utilized until we tear down one ourselves, but it looks to be a version of CWT's PUQ platform. As expected, the ET550-HG has only a couple of PCIe connectors, whereas the two models are equipped with four. We expected at least the ET750-HG to have two EPS connectors, but it seems SilverStone was quite conservative in this matter. Finally, all cables consist of darkened wires and are flat, with only the absolutely essential ones (ATX and EPS) being fixed.