I picked up a couple preowned Penman hats this year. One is 100% rabbit and the other is the Everyman 80/20 mix. They are good and sturdy. Cannot comment much on the Penman 80/20 as I only wore it a couple times (have many hats). I have worn the rabbit one a good bit in rain and sun with no issues. I actually lowered the crown down and did a teardrop on it.
Getting back to your original question, I have worn the crap out of my 80/20 Henry and Harrison Indy ones. Have worn them in pouring rain and heavy snow and they still look very good. I do brush all my hats after wearing them and take pretty good care of them. I figured they would wear out after a couple years of use and bought some 100% beaver ones to eventually replace them. Have not had to take the beaver ones out of their boxes yet. The 80/20 blend regardless if it comes from Penman, Adventurebilt or Advintage are some durable hats.