I've been pretty happy with it on my car so far.
I just went for a flick through my blog to see where i used it. I only bought 1 litre and still have some left:
So all of the firewall, the rear load tray, all the seams and gutters, both subbies, all suspension components, all rust repairs, steering column, pedal box & pedals.
It seems to be pretty tough stuff so far. No adhesion problems.
I even painted my boots with it (with left-overs). The toe where the steel cap wears through from kneeling and the back of the cap where the gear level on the motor bike sits have held up extremely well. And that is adhesion to flexible leather.
I do remember reading that the competition was better in tests before I bought the POR. At the end of the day, I didn't want to pay postage and wait for stuff to arrive from the USA when I could go down the road and by the POR-15.
I tell you in a few years if that was a wise move or not (providing I still have the car). Living a few hundered meters from the beach in Qld tends to sort old cars out.