I'm using PBL on my DD and some customers, unfortunately from what I see it's still scratch able. Maybe slightly less, but nothing significative.
What I've noticed is that it offers slick durable protection that allows you to wash and maintain the vehicle easier and with much less risk of instilling swirls back while doing it.
You can rinse (I foam and rinse) much more clean before the formal wash. Sometimes (on my car I don't have enough time to maintain) I just foam and rinse, and dry with water sheeting the most I can, it goes back to shiny state just like I've washed and waxed (have to do this weekly to work best, but it's soooo fast...).
Scratch resistance on PBL is not a problem to me since I've not ordered it based on scratch resistance claims, but based on durability of protection claims.
In this case, durability of protection is showing results even above the claims, if you want to stay months (the durability I was able to see until now since it's new) without waxing / sealing and not worry about it, I cannot think of anything else. I suspect it'll last close to 3 years claimed, but if last 1.5 year it'll still be the best around.
I'm trying to educate customers this way: after applying the coating, they come back in between 15-20 days to watch a wash. This is the time I'm seeing they really trust what I've applied - I'm 'proving my claims', live.
I've tried it once while waxing, but customer travelled a lot and got some constant rainstorm in the period. Wax washed away, and I couldn't believe the state the vehicle turned out in ~1 month.
That means I couldn't trust the wax, as I blindly trust PBL protection. I had to re-wax (for free) in consideration to what I've claimed (but didn't happen with the Wax protection).
That's it, PBL is all about protection, and having it on my own car makes it possible for me to follow up my work. Mine was the first applied (NOV/13), so it's beading strong like the first day, washing is still easy... customers (I've applied later) should be equal or better.
I also have a scratch resistant protection google (polycarbonate lens), which I never tried to scratch or test it's resistance. It's scratch free for about 6 months, and that shows it resists light scratches.
However, if I get some dirty wash mitt or brush I've seen at fast-wash service, I'm pretty sure it would scratch my googles!
Hope I've helped,
Kind Regards.