Thanks to all for your honest and knowledgeable comments. In view of no first hand reports of any actual Sailun tire failures I am confident that these tires will be a good tire choice. After I use them awhile I will post a review. Thanks again.
I have made the decision to replace my GY Marathons (E)rated tires on my 15000 LB fiver. I am also replacing the wheels with 110PSI rated wheels. I'm leaning towards going with Sailun 637 235/80R/16. I had never heard of these tires a week ago when the rep at Big O Tires recommended them. I have looked at reviews and all seem to be good. If you have any first hand knowledge I'd like to hear from you.