<< You should be able to bring an XP2000 to a competetive speed as a P4 1.8 (OC'd) via OC'ing, >>
you'd have to overclock that chip from 1666mhz to at least 1900mhz. i don't know of anyone with air cooling that has gotten their athlon that high. and if you want to overclock that athlon at all, you are going to be spending ~$50 on a new hs/fan, one that's undoubtedly loud. and that doesn't take into consideration the case fans needed.
so, for about $30 more you can have an athlon that is much louder and runs much hotter, and if you are very lucky, performs about the same as an overclocked p4-1.8ghz.
<< If you have the money to blow and want the fastest... why not a AMD ATHLON XP 2100+/266 FSB PROCESSOR CPU - RETAIL BOX for $231.00 +$6.95 shipping (Only $43 more than a 1.8GHz P4). >>
ummm... a p4-1.8ghz @ 2.4ghz will leave that 1733mhz athlon in the dust.
<< Overclocking still doesn't scale as well as an XP cpu (66MHz ~= 100MHz on a P4) >>
great... another zealot who has embraced the pr. that formula may have been true with a willamete, or maybe even a 400fsb nw. but at 533mhz, the bar has been raised.