Indeed. I've had the same experiences. Not sure if the enthusiasm/eagerness is all related to their looks/not getting enough attention as a result or just that they are like this anyway. Either way, its fabaroony to experience!!!
The best sex and best blowjobs I've had are from average looking women, plain Jane type like this woman. They're grateful for sex and eager to please, and can suck a golf ball through a garden hose.