I tried wearing my P100 respirator to CVS and Safeway today, I didn't know what kind of reactions I would get but really nobody cared, I didn't get any comments or stares or anything. The only issue was that I had trouble speaking clearly, I wish there was a half-face respirator model that had both a speech diaphragm like the Secure Click and an option to add an exhalation filter like on the 6200.
I never get anything other than kids thinking it's cool as hell or the occasional "nice mask" from someone with an impossible-to-decipher tone when I wear my 6503 out.