This has been beaten to death in a dozen posts already, and I have merely one word to say: COMPILER!
Use a compiler that's ill-suited to the processor being tested, and SPEC scores will be abhorrid. Use an excellent compiler and Spec scores can be wqell over 1000% better then they might otherwise be.
It's been shown about a thousand times now how ill-suited the compiler utilized was to PPC, and the G4 specifically.
The processor alone is but a small part of Spec, there are many other aspects that can heavily influence the score.
Wait until we see Apple's own Spec scores before making any sort of judgement.