I drive Sotars commercially, on half and full day trips in the Royal Gorge. I have observed wear on the bottom of the boats in spots where there is an overlap, or bulge. I attribute this to the aggressive loading and unloading we do constantly, twice a day, along with sometimes dragging the boats at the beach. We have had a few patches- perhaps 5 out of 40 boats over the last 4 years. We have lots of sharp rock in the Gorge, and with low water the last two years, we hit plenty of rocks. I have been satisfied with their durability. We have factory installed urethane wear strips on the tops of the tubes that have adhered well.
I have driven NRS, Maravias, AIREs, Vanguards, Achilles and Wings over the years, and with the exception of Wing, these Sotars are far and away the nicest boats I've driven. They're light, they track like crazy but still turn easily, they bail quickly. Before driving these boats at work, I probably would have gone for an NRS or Avon for my personal boat. Now I own an 18' Sotar.