I recently rode with a group on an easy ride. The comment I got was how steady the speed was when I was leading. Fixies are like airplanes in that they have a favored cruising speed. If you're riding with a group of geared bikes you have to be really aware when your in a paceline. Fixies have by nature some differences in the way they gain and lose speed and can cause geared riders and yourself some problems if you are not careful...
I do get some looks. Usually any question are only after they haven't dropped me.