Now pitsi, there are lots of places you can go for laptop reviews. <A HREF="http://www.tomshardware.com/mobile/index.html" target="_new">THG's Mobile Devices</A> section can help you a bit with that, as well as <A HREF="http://www.anandtech.com/mobile/index.html" target="_new">Anandtech's mobile</A> section and <A HREF="http://www.xbitlabs.com/articles/mobile/" target="_new">Xbitlabs' mobile</A> section. You can look for reviews from individual models. However, it is nearly impossible to find a generic review of each platform, because laptops come as fully-configured packages, and review sites can't quite compare each setup because they might be highly different configurations - different video cards, for instance. BTW, video cards for laptops are specific, too. THG did a <A HREF="http://www.tomshardware.com/mobile/20030324/index.html" target="_new">review</A> on the latest DX9-compliant laptop video cards that might come in handy. They mention the R9600 Pro Mobile, for which you showed interest. Unfortunately, I do not know any company that is currently shipping laptops with that chip... but I have not been following the laptop market that closely. Dell doesn't have it, I checked right now... Not even <A HREF="http://www.alienware.com" target="_new">Alienware</A> got the Mobility 9600 Pro. But you'll find the Mobility Radeon 9000 easily... If you really want the 9600, it might be a good idea to ask a local representative of one of the major companies or something.
Anyway, because of this lack of a generic platform review, you might have to look around for specific cases until you get the general feeling of what you get with each option. That statement of mine, <i>"is on par with a 50% higher clocked Pentium 4"</i>, is a result of looking through those reviews, and holds relatively well. But it should be interpreted a bit loosely.
And as for other companies creating chipsets for the Pentium M, I am not aware of any. I think it's just Intel, but I'm not completely sure of it. Anyway, anything called "centrino" already includes i855 - an Intel chipset.
<font color=red><b>M</b></font color=red>ephistopheles