The better question with Antec is, should I get the Smart Power or the True Power. There's a big difference with them.
Smart Power Antec's use the same method as everyone else. All rails are ran off the same transformer.
True Power by Antec uses a entirely different set up. True Power has a separate transformer for each of the voltage rails being 3.3, 5, & 12 volt rails. So you have clean adequate power for all the rails independently of each other. So you see True Power whether it be 300, 350, 430 watts are far superior to Smart Power & other PSU's.
The only Antec to get is the True Power if you want to step up to the plate with PSU's. The Smart Power is OK for most applications though.
I only run & build with Antec True Power. There are other advantages with True Power & if you research them you'll see the difference right away.
If it ain't broke, take it apart & see why not!