Pound for pound AMD is a better buy.
cheaper than intel for same perf.

Ya, the 3GHz machine probably is overkill on a home machine.
Hell, I'm still running a PII 400MHz and have no complaints.
My 1.2 machine at work boots up faster, but that's the only
difference I've seen yet.
Put up for a decent graphics card and I don't think you'll have too many games that will
crap out... course I"m still playing starcraft, so if that's any indication.
Return to Wolfenstein looks good on my piddly 400 with a radeon 32DDR card.

You'll probably notice more by paying attention to the bus and memory speed. (stick with ddr by the way)

That's all I have to say about it.