The AMD chips are good, especially for gaming, and they do run quite cool and chew less power (important for overclocking and preserving the battery), but they're not miles better and in a number of productivity apps they're actually quite a bit slower than a P4 (particularly video editing/encoding and 3D modeling/animation apps). 64Bit really isn't that big a deal yet and does it look like becoming a big deal anytime in the next year. The P4 is not a really bad chip, it could be better but it's still superior in pure performance to the mobile AMD64 in a number of instances.