OK, so here's what I've taken from the discussions in two threads now as a person who doesn't own either Dura Ace or post-1990s Ultegra:
TI cogs wear faster for some people and not others (this makes sense for me because people's gear usage, etc. will be different).
Other parts last too long for people to live long enough to wear out a decent sized sample of the two groups. At this level, stuff other than chains and cassettes is good for too many decades for the differences (if there are any) to matter. We're probably talking about whether or not the drivetrain will still be in good enough shape to pass on to your grandchildren. Who cares?
People usually like what they have.