I drive the speed limit when there is only one lane but when there's passing lanes I'll drop to 5 below. I'm very cognizant of drivers coming up behind me, mergers etc and adjust speeds and lanes to try to make life as comfortable as possible for everyone. I still get people that will fly by me at light speed cuz they were delayed by 1 second to get to the next traffic light.
I notice that I am treated very differently depending on which car I'm driving. I have an old beat up 94 Nissan D21 pickup that I can drive at 55 in a 65 and no one gets pissed but if I try that in my wife's Lexus or my newer more modern looking car people get their panties in a wad. I think they just figure that the old dude who can barely afford to even drive (the D21) has enough problems to deal with - cut him some slack!