Five minutes wouldn't bother me that much since most of my kids come from at least a 10 minute drive away which translates into several stop lights/stop signs so the length of time needed to get to my house can vary by their luck at the lights. At the same time some mornings go more smoothly than others and seems silly to just stand there watching the clock.

Had a family that often arrived 5-10 minutes early and they would sit in their car in my driveway reading books, singing songs, etc. till the appointed hour and while it was the right thing to do it did seem silly when the kids could have just come in and watched tv till everyone got there but I did appreciate that they respected my time. I have a 5 minute or so grace period on both ends of d rop off and pick up.