Sure, I did the hack and undid it in the 5 minutes I was finally able to get the iBook to boot after it started dying again
Apple fixed it all under the guise of the extended warranty, and indeed, perhaps it was the original defect and not the hack, I think no one can really say.
But, in the off-chance that the iBook is a person's primary/only computer, I err on the side of caution. I have 3 Macs (and 4 others in the house) to use when my iBook is being serviced, but not everyone has that luxury.