Here is a link to a competent technical review of the power supply:http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=173
Antec's new CPX form factor is non-standard and was meant only for use with their Twelve Hundred, the P183, and the P193 cases. It is not designed and will not fit in standard ATX cases.
Corsair and Seasonic are two brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty (in the USA).