"1MB power managed L2 cache increasing system performance" - these processors have a bigger l2 cache which makes them faster than their clock speeds would indicate.
I've used a few notebooks with Pentium M's and they all seem to compare favourably with the p4's. The other good point with these is that they have a low power consumption so your battery lasts loads longer.
For more detail click here&
and click on the pentium M option.