The OCZ ModXStream 600 is a lot of power supply in a relatively small package. Boasting 25A on each of its dual +12v rails, plus an additional 25A each for the +3.3v and +5v, the ModXStream 600 seems at least as capable if not more so than many power supplies with higher wattage ratings. It had no problems handling an overclocked quad-core processor and a single high-end video card under load. Although it touts being able to power both NVIDIA SLI and ATI CrossFire modes, with only a single 6-pin and one additional 6+2-pin PCIe cable, it is not going to handle two high-end cards, most of which require multiple power connections to work.
The quality of the ModXStream series is good, with a durable, attractive finish, nylon mesh sleeved cables and color-coordinated connectors. OCZ has even thrown in a handy accessory bag to keep your extra cables in. The only fault I found in the ModXStream 600 was that it emitted a ticking sound when powered on, that was a result of the fan blades hitting a flexible plastic divider inside. But the noise only occurred when the power supply was operated on its side. When mounted in a case in the typical orientation, with the fan aimed down, the noise subsided completely. This is probably an isolated incident. I also noted that there is no kind of "warranty void if removed" sticker present. Strange but nice, considering OCZ offers their 3-year exclusive PowerSwap warranty replacement on the ModXStream series.
Update - I opened the case and moved the plastic guard so it no longer contacts the fan, problem solved.
The ModXStream 600 is available through the usual channels for just under $100, which puts it in the 500-750W ballpark for most manufacturer's power supplies. With OCZ offering rebates on many of their products a good bit of the time, it's likely you can score this little powerhouse for closer to $75, which makes it a bargain in my book.
The OCZ ModXStream 600 has earned the OCIA.net Seal of Approval.