I ran my old Cherokee with stock dana 30 shafts and joints with 37 maxxis creepys. Ran that way for 3 or 4 years with 1 joint failure. I agree driving style has everything to do with longevity of parts.
Although I am still happy with my trailer purchase from wasatch. I did find out after I recieved all my paper work that my trailer was 2 years old.... At time if purchase I was told it was "brand new" yes it was to me but was built two years before that. I was also told my trailer was a car...
Also, notice what siping/grooving they do have only goes half way down into the tread... Wait till you have just under half tread left and they will look like front steering semi tires.