Meridian's new XCLIO-550BL is definitely a solid performer with good voltages and capable of meeting (and exceeding) its rated specifications. In fact, I was able to push this power supply to a peak of about 700-750W (however it did shutdown safely within about 30 seconds). Even under that heavy load I checked the 12V rails and they were still within 1% tolerance! Under very heavy loads & temps, the fan does kick in at full speed and can be noisier than some would like. A couple more SATA connectors would have been nice (currently only has two), especially considering this is a 550W model.
This power supply is made by Channel Well Technologies, the same people that make power supplies for Antec. As mentioned before, the new XCLIO models (with the rubberized coating) have essentially the same "guts" as the Antec True Power 2.0 line. The main difference is the number and types of connectors, and also the rubberized coating. Cost-wise, the XCLIO is *slightly* less expensive from places that I have looked online.