This is the impression I have so far: True tung oil seems much better for developing patina, fixing scratches, etc., but twice as expensive. Argh. (Why is everything good more expensive???) Also, be careful of various blends out there.
This Old House forum conversationWoodworker's forum (more details on various blends versus pure tung oil):
Apartment Therapy discussion that mostly confused me
How to finish with tung oil (note: it doesn't work with miniwax stains):
Kind of funny -- how a tung oil floor is like a well-seasoned frying pan
A (no doubt biased) tung oil supplier's detailed explanation
Wikipedia basic facts on tung oil
I only have experience with polyeurethane. I will say that the ability of the polyeurethane to withstand scratches has to do with the expertise and willingness to spend time and money of the installers. If you use plenty of product and take your time, it is a sturdy finish. If you skimp on product and are uneven with the application, then it really looks bad in just 3 or 4 years.