Watch this PS. It only has a single 12V rail, and is not a 430W as advertised. Only buy this one if you have a very basic system. There are much better deals out there for the price than this one, like the OCZ 600W for only $4.00 more.

does it constantly use 430 watts?? or does it only use as much as the system is needing?

This is more than adequate for 95%+ of the population.

seriously i think this site has become just an advertising stream for these companies. Where are all the "deals"?

haha, you think #4??? that happened years ago.. its just one big commercial

#3 -- Is correct.
Now this Thermaltake been at this price on and off for the last year and was a good buy back then at $29-26. Sure early on the talk was it was good for 85% of the advertised watts; although when it comes to lower end PSU's no one should infer you should or could push them past 75% of the rated voltage. What I liked on this was good regulation and over currant.
That said the Stealth Stream are said to be better than good and the 80% efficiency rating would seal the deal.
http://bensbargains.net/forum/viewtopic.php?t=86335&highlight=ocz600sxs+stealthxstream
As one steps-up to more demanding and expensive components, you really need to do your homework. It's a weighted judgment against the intended use, the load, efficiency, and cost.
I've used this 430W for a couple nice moderate systems. They're perfect for the requirements at the start, while providing modest headroom for minimal upgrades.

#2, no it does not constantly use 430 watts. A good power supply would be 80% efficient so a 430 watt one would provide 344 watts to your system. From what I read this one cannot really do 430 watts and I doubt it is that effecient either. All electricity degrades to heat, so other than the light or heat that is leaving something (which is usually a tiny amount of actual energy), you can make a (very) rough estimate on how much power something is using based on how much heat it generates. My case feels like it is less than a 100 watt lightbulb. I could be exact and plug it into a kill-a-watt to measure the electricity used at any moment or over a time period.