Hanabal, I think you're wrong.
...about the burn protection anyway; AFAIK the AMDs will shut down just like the P4 does these days.
Generally speaking, the older AMDs (pre-AMD64) have a "false" performance rating. For example, the 3000+ is comparable with a 2700 mhz P4 (if it existed). The AMD64s are more accurate with their speed rating.
The only real reason to buy a P4 would be movie editing; AMDs have a bad reputation for unstability with at least some of the associated programs. Other than this, it's a simple cost/performance issue - get the speed you need for the lowest price.