I'm fully aware of PSU's "Active PFC" and that they won't consume the written W all the time. (Makes sense). But now I'm before a PSU replacement (Guys: NEVER buy a Chieftec. Seriously.)

The question is: If one can get a bigger one (in my case 750W and 650W) ... should that person go for the bigger one ? (The difference in price is not much). No, I don't think I'll soon use all that much.

(Please help (if you want of course) to make the question more generic if the question is really not OK in this form. I've been wondering about this for a time already. In my case it would be XFX Black Edition Silver 750W and 650W)

(Basically about "which one" I would go with XFX/Antec/something which comes with industry qualified parts. Like Duracell but in a PSU. :) But the performance is a different thing.)