Wow! Very interesting. Nice work...you got balls man!!! I think 99.9% of the people assumed you were a plain clothes LEO. Are you mid-30's to middle age white man who is clean cut? I would have...and I CC everywhere in Philly.
Try the Northern Liberties area, the subway, Old City...or at a convenience store or a bank to see how people react. I am VERY curious. Pop on an NRA t-shirt too
Al