A 480W Antec sounds a pretty potent beast, but with a 22A capability on the 12v, that's where you could be feeling the pain.
The CPU uses a 12v feed (switchmode regulated to trade voltage for current, down to whatever the core voltage is), as does the graphics card.
Fan motors, of course, are 12v, as are the drive motors.
The one thing with a dual 12v alternative, is how does it/can you disperse things betwen them?
Clearly, with 2x 15A, the CPU goes on one, the Graphics on the other, and the other stuff dispersed evenly, biased towards whichever main component uses the least power.
One thing's for certain - any replacement for a good 480W needs to be of higher power, and of at least the same calibre, and/or with good, honest 12v ratings that are up to the job.
These days, you generally only need to compare the 12v rating, as if that's good, and the overall power is ok, then the other rails will be plenty.