All Tri is saying that people on this forum have recommended psu's that are a huge overkill. I agree with Tri. I would still recommend a 500watt+ psu for medium to high pcs. Only for 8xxx series SLI would you need a 700watt OCZ psu. My system was once powered by a 450watt fsp psu and it ran fine, stable for that. (overclocked cpu and video card.) Only reason I upgraded was all of the wires and I liked the look Hipers 580watt. (Not to mention hiper is a good brand.)
^Hope that answered your question. I know it is a poorly written paragraph with 0 organization.
PS: Amps is most important.