bit-tech published a review of Cooler Master's UCP Ultimate 900W PSU
This would make a fantastic PSU for Folders: it's exceptional efficiency at very high loads, which means that it will save you the maximum amount of money while you help to find cures for diseases. At a nominal 20 percent load the rest of us will be using for most of the time, it's no more efficient than any other PSU and without spending all day at load to recoup the cost difference through power efficiency benefits, you'll need to use the UCP 900W for several years to make up the extra money you'll spend on it.Cooler Master UCP Ultimate 900W PSU Review
While the graphs above might be very nice for a direct comparative, and paint the Cooler Master UCP 900W as a bloody awesome and very well engineered PSU (which it clearly is), the price premium simply outweighs the benefits of 80 Plus Silver certification. As a result, the UCP 900W doesn't do enough to justify the asking price, but if you are looking for one of the best PSUs on the market today, regardless of cost, it is definitely right up there.