Normally, I do not post conclusions to reviews. I encourage readers to read an entire review because a mere conclusion paragraph misses many nuances of a product. The conclusion is merely a summary and can often be either overly optimistic or pessimistic of a product depending on the particular reader.
I will make an exception for the Ultra X2 750W review at HardOCP:
The Ultra X2 750w Extreme Edition presents bad build quality, bad voltage regulation, and could only deliver 364w of the advertised 750w of DC output in our testing environment. The Ultra X2 750w Extreme Edition is a lot of things, but one thing is certain, it is NOT a 750w power supply.
For some reason Ultra has taken a mediocre 400w power supply, slapped a 750w label on it, and shoveled it out the door to store shelves. Why it would do this is beyond us. If you are looking for a good 750w power supply the Ultra X2 750w Extreme Edition is not it. Even if you are looking for a good 500w power supply, the Ultra X2 750w Extreme Edition is not it.