Three-penn'orth to add to the above informed comments.
Why laptop? Will it be mostly mains-powered and is preferred for its portability?
Or will it be used in the field and on batteries? If so, consider the battery life and whether the processor can benefit from the sort of power management used by Sony on the Transmeta Crusoe in my Vaios. CPU frequency (and power consumption) can be made adaptive to the processes running. This feature can be seen to be working and be irritating but it can also be disabled for static use on mains power allowing the processor to run at full speed.