Laptop configs play a big role too. I have an AMD64 DTR laptop. DTR=desktop replacement=burns battery in much the same way a Hummer burns gasoline. I have a Pentium M laptop as well. The AMD64 DTR gets twice the battery life that the P-M does. Of course, somebody's going to start screaming that it just can't be so, but I assure you it is. The OTHER hardware in the P-M box is half of the reason it burns so fast, and the miniscule battery it came with explains the rest. So if battery life is going to be an issue for you, make sure you look at everything, not just which CPU you're getting.
I definitely agree that my AMD has a snappier feel to it than my P-M. I don't run numeric benchmarks for many reasons, the only benchmark I trust is my own experience. For 90% of what I do, I have no real preference between the systems as far as performance. The AMD64 box keeps up with me a little better when I'm doing 20 things at once, but fortunately that's a pretty rare occurrence. They're both adequate gaming rigs, and virtually all of the differences are explained more by the supporting hardware differences than by the CPUs.