And a x86 modern cpu completely wipes the floor with a G5.
Kind of irelevant though for MOS fans though seeing as MOS doesnt run on that hardware. (see any sort or parallel there?)
As for buying an X1000, the only sane reason a person would buy one is if they want one. On mass it wont retain its value in 25 years time the way the classics have, but if you're buying for an investment you're barking up the wrong tree anyway.
Buy one if you want to use it. No need to try to justify it. Not everyone will want to spend thousands on a machine whose specs are matched, and beaten by the sort of pc you'll find in the dumpster, just so they can run a particular OS, but if a person is inclined then far be it for anyone else to tell them they shouldnt.