Careful you don't jump on any bandwaggons, there, Shawn.
I would have said that although it seems highly likely that the Airbus accident was due to PIO, if you are putting in 150lb rudder force stop-to-stop inputs, it doesn't really matter whether the BO+F is 25lbs or 50lbs, you're going to push straight through it.
Don't get me wrong, I don't believe that particular design of directional control stands up very well to scrutiny (even though it was designed for the cruise phase, where rudder inputs have no role-relation). But let's not cloud this issue. I think there are too many people on both sides of the argument who try to make political capital out of accidents.
I would say that in this case the PIO was due to a large delay in roll response (due to roll inertia, normal 'transport type' roll response and the delayed roll response as a secondary effect of beta), and as anyone who has experience of this sort of thing(as I'm sure you do) will tell you, that sort of delayed aircraft response is a real recipe for PIO.
IMHO this accident happened because the pilot was doing what he had been erroneously trained to do - using full rudder displacement to roll the aircraft in a manner which I'm sure makes the subtlety of the directional control system harmony irrelevent.
Just my thoughts on that particular one.