No offense, but do not put all your faith in one site alone. Tom's is reputable, but I feel myself questioning the outputs of those benchmarks. I have seen and read on numerous other sites showing the Athlon MP (Palamino) showing MUCH (relatively speaking) improved preformace. 10% was range was not uncommon, just an average. Considering SSE is used in more than a few applications, this will be quite a big boost in "free" speed. Also, the new incorporated data prefetch should become a lot more apparent in it's speed boost as time goes on.
In addition, are you forgetting the lower power consumption and lower heat output?