I also have a Allied Psu [450 true], I bought it a year ago after a 400w el cheapo psu that came with my case died during a game [only had it a month to].
The rails on the allied are great - 12.2 on the 12v, 5.1 on the 5v and 3.3 on the 3.3v line during load.
And thats with 2 40gb hds in Raid 0, a 80 Gb drive, radeon 9500 pro, a overclocked 2800+ cpu, 5 case fans, and a sound card and some other stuff.
Considering the Antecs go for $70 and up, $50 for the 450 model is a great buy.
The 400 models though i would be somewhat weary of as ive heard they dont weigh nearly as much as the 450, which would suggest it uses cheaper components.