http://www.arstechnica.com/

''"The PC enthusiast's resource"''

A site which has a wealth of information about PC's, hardware, and software. 

Much of the information is geared to power users and developers. Very little puffery and hype ''ala Pogue''. 

This one in particular has a good comparison of the PowerPc G4e chip and the P4
http://www.arstechnica.com/cpu/01q2/p4andg4e/p4andg4e-1.html

There have also been some very thorough reviews of MacOsx.