I received my 509 right after Easter and have only managed two short range trips of 180 rounds total. Ammo was Federal XM9001, S&B 124 white box military contract, and Federal aluminum case 115 grain from Wal-Mart. If this gun is actually a blem, there is no discernible evidence of it. Several other instructors at work have purchased these as well and have stated the same thing regarding the "blem" status.
The trigger is gritty on the takeup and release but is slowly improving. I suspect it will smooth up after some more rounds downrange. No problems of any sort and I managed to get more hits on the torso sized steel plates at 25 and 50 yards than with the G2 G19 with Ameriglo I dot sights I have had and shot for years. Quite enjoyable and would probably be a good duty handgun if parts/armorer support are made more available for institutional users.
My understanding is that Brinks has adopted the 509 as its standard handgun for its armed security people. It would be interesting to see what kind of support was in the contract.