Agreed on the radial performance vs bias. Heat dissipation and overall ride quality just dont compete. When I was looking at the PA tires there were 2 issues - weight rating and speed rating limits. Most of them were rated well below highway speeds - especially the current unofficial speed limit. This isn't a big deal if you are running to the local lake, but if you are doing longer trips the bias can't deal with the heat and runs really hot. This causes uneven wear, and if underinflated by just a few lbs, can cause a blowout. I ran the bias from Paris up to Cochrane and back, at the flow of traffic speeds, on the bias tires that came with the trailer (same make as PA sells) wore really badly even though I checked the pressure before each run - heat from the high speed (checcked them at each stop - they were hot). Then coming back from Jordan a week later one of then through a chunk out of a nearly new tire. That was it for me. Bias ply was removed from almost every other application than small trailers years ago - there is a reason. They just dont compete from a ride, heat, longevity and speed capability perspective, They do have a stronger sidewall, but the benefit here is liimited to the most brutal of applications (rough roads), and driving according to conditions will over come that (and save your boat from rought trailering damage).
If you want an intro to Tom at MacMillan for comparison pricing drop me a pm