I have no intention of getting into this tiff but your statement "Do you have any idea what dog urine does to a hard wood floor if it's not cleaned up right away?" interests me. I have two homes, both with hardwood floors. I also have two dogs, both very well house-trained, but it is entirely possible that an accident has occurred that I did not see.
What damage does the urine do if not cleaned up right away?
It stains a waxed hardwood floor dark brown or black, it's the acid. Vomit if acidic will do the same thing.
It won't do a thing to the polyurethane, just sits there.
I've had both, had a waxed hardwood floor for 12 years and a poly for 10. Only problem with the poly is that it does scratch eventually, even the good stuff, and has to be sanded off and reapplied.