</font><font color="blue" class="small">( Ok I understand Pentium 4 but not M. I understand Celeron but never heard of Centrino.)</font>
I used to own a computer store until I grew a brain and sold out. /forums/images/graemlins/grin.gif Anyway, this actually was before the advent of the processors that were designed for performance with minimum power consumption; i.e. the Centrino.
Although it is just a "feel", and benchmark tests don't always agree, I think the regular ole Pentium 4 seems to feel a hair faster than a comparable Centrino. I have laptops with each (I have 5 kids, I have lots of laptops /forums/images/graemlins/frown.gif) However, here is the huge difference; battery life.
It is a joke for the manufacturers to give directions of how to watch a movie on your laptop during a flight if you run a Pentium 4 processor! About the time you get to the good part of the movie, your battery will be done. A Pentium 4 laptop I have that runs at 3.2gHz gets about one hour and fifteen minutes to one and a half hours of time on a fesh new battery.
The laptop I bought with a Centrino processor runs almost exactly as fast (only ever so slightly slower) but I get an average of three and a half hours on a full battery. There is a huge difference in battery life. That is your difference.
When I owned a computer store, some makes of computers were flat junk. Have you ever seen X'd out golf balls? About half of the Packard Bell computers that came in for us to fix had X'd out chips on the motherboard!! /forums/images/graemlins/shocked.gif Also, they used a propriatairy motherboard, so we had to put the same junk board back in that we knew would only fail again. Anyway, there were a few brands that we ended up refusing to work on. We posted a notice right at the cash register. It was easier to hear the customer complain that we wouldn't work on their computer than be stuck with them being upset because a computer of theirs that we just fixed broke again.
Fortunately most of the really bad makers went under. Others changed. You mentioned that you like Dell. I don't think you can go wrong with those. I've also noticed that Toshiba and HP also build a nice laptop; especially for the money. Sony laptops seem nice, but they simply seem expensive in my book. I may be completely wrong since so much time has passed and they are still in business, but Gateway used to be a brand that would make us cringe.
You may laugh, especially after knowing that I owned a computer store, but I now generally buy my younger kids eMachines for desktops. /forums/images/graemlins/blush.gif A good, well made, computer will depreciate more in one year than the eMachine costs. In other words, I figured that I could just go buy a new eMachine each year for the same cost and always have one under warranty. The real shocker is that even the first eMachine I bought my 8 year old still works. /forums/images/graemlins/smile.gif I'm not promoting eMachines, but I'm only professing my shock that I've never had one break and that they "feel" fairly decent. I have no idea if they even make laptops. Besides, your daughter would be ridiculed if she carried an eMachine laptop. It would be like sending her off to school driving the vintage Vista Cruiser station wagon. /forums/images/graemlins/grin.gif