Duke..
Yes, I'm very happy with my P4 Again a yes, I'd much rather have the heat spreader than a tiny, bare core any day.
IMO, I think you'd be able to tell the difference between a XP1800 and a P4 2.4. Games today are happy with a XP1800, so probably not a huge difference in that area, but encoding, decoding, ect.. would increase noticeably, 10-20% maybe.