I got the 550 one, but I sold it (only cause I sold it to a friend at purchase price) because I was afraid I might need more power, also the cables were short, not great for cable management, hopefully they have fixed that with the new 750, because otherwise the 550 was awesome! very quite, no fan noise or electrical noise. I got the 700W one later, but it's just a re badged older model, and its 120mm fan was terribly noisy, thought it was a fault, but tried another and got the same result... got a Thermaltake TP eventually, but I miss the 550 OCZ!