Jimh is the only one that has given you accurate info so far.
There is no disadvantage to 65psi, the max pressure rating IS 65 psi and the load rating is correct. Tire is wide and tall enough that, that pressure gives it that full load rating and the wider and taller the tire, generally the more load it holds for a given pressure and the wider the tire, the more it balloons at higher pressures. And no it won't feel squishy compared to 80 psi in a narrower tire.
This is consistent pretty much across the board for tire ratings.
Never had a set but they look awesome. Huge tread depth and always thought Yokos were top quality. Curious what Spectra doesn't like about them.
Only comment is if you're using them in the upper end of their rated capacity and have OE rims, 8" rims are a bit narrow for that tire. Not overly narrow but not optimal for best tire wear. Ideally 9-10" wide rims with 12" wide tires.
