Very Interested in purchasing one lof these cards but I have been told they are very demanding on the PSU, and that they plug into the PSU. Do these cards just plug directly into your AGP slot then a power connector from the card to a PSU lead? Also what kind of PSU would I be looking at it to run this card at it's max performance?

Yup you are right as far as how they hookup, and I have a 9800 pro and a 300 watt PS and it works just fine.

Yes, ati recommends 300 watts, but I have a 9700 running in my kids computer with a 250w and it is fine. Im sure the 9800 would be the same. I'm running a 9800 pro in my computer with a 350w power supply.

im running one as well, but im also using 450w psu.. no worries though