Are you sure your information is up to date? Budsgunshop has the 5" pro and the M&P9L for the exact same price. I have not been able to find the 9L for less money than the pro in online stores, and the 9L is hard to find in stock anywhere. I would by the pro given that the price is identical to the 9L online. If you find a 9L in stock somewhere local for less, buy it.
That's why I bought the pro from buds. I went with dropping my gun off to burwell gunsmithing instead of putting apex parts in.