I'm not a builder. And most of these guys have more flintlock experience in their little finger than I do in my whole body. Heck, I'm not even a good shooter. But this is what I have observed...
I have two custom builds and a Pedersoli Kentucky in .32 No experience with a Pedersoli built GPR
Both of the customs have L&R locks, a Bedford and a Queen Anne. As I understand it, some folks don't hold L&R locks in the greatest esteem... But once i learned the particulars of each lock and learned to do my part they've worked fine for me.
The Pedersoli lock is reliable if you keep the flint sharp... But that can be problematic. Both the mainspring and frizzen spring are orders of magnitude heavier than they need to be. This makes for a heavy trigger pull and a good bashing for the flint to get the frizzen moving. This was not real apparent to me until I had better locks to compare against.
If Pedersoli is putting their lock on the GPR they manufacture that would have me saving my money for a while longer and getting a custom gun instead.
Will the Pedersoli guns work? Absolutely... with enough effort and a good supply of flints. I like nice guns, however a plain stock and heavy barrel can be worked with... but a lock that fights you every step of the way will make for a frustrating experience.
If Pedersoli would improve their locks or even use locks from one of the many quality makers on the market they might get something going. I find it telling that L&R does a good bit of business selling locks to upgrade factory locks.
Just my opinion based on my own observations.
Mike