Its not give or take, its just take. Apple takes the profits, and they take away the 167 full fledged bus. My Centrino machine have a 400 Mhz FSB, running at 1.6 Ghz, it weighs less than 6 pounds and has mostly metallic casings. Fan never turns on unless i run benchmarks or play games. And if you refer to Cinebench benchmarks, a universal cross platform benchmark, you'll see the aging G4 architecture waning. The G4 was competitive with the PIII, not with any of the newer chips in either camp, G4's destiny is perish or become a strictly embedded chip, or be revamped and spun the silicon a few more times. The only good part of the G4 is the vector unit, which we all praise, but that's the unit that requires the most FSB bandwidth, at 133 Mhz, the G4 have troubles filling the VMX unit with instructions, and compete with that is the regular floating point which is concurrent with VMX and the integer pipelines, you have a big choke point.
Get the G4 out of the door, or get the G4's updated, either way, the current iteration of G4's are competitive with yesterday's machines.