Here's a beneficial feature of PARRs that I hadn't noticed before.
The downward interest rate resets are always based on the 30 year CMT rate. That doesn't mean much now as PARRs still have about 18 years until maturity. But eventually they will become short term bonds with interest rates still based on that fat 30 year benchmark.
Of course, that quirk won't help much if interest rates soar. You don't want to own these if inflation and high interest rates return.