Your second one seems more accurate. If you can, go with a Pentium M. The performance issues on a high-end Pentium M and Pentium 4 are not too different, but you will find that the Pentium M uses less power and produces less heat. Pentium M’s are, because of those two advantages, great for laptops.
The only problem is that Pentium M’s do cost more than Pentium 4’s though.