i dont think regular heelflips are any harder than switch/nollie heels, i just choose to do them switch/nollie more because they look cooler than regular, regular heels are cool but rarely do they look cool when put into tech tricks, one dude who can pull it off is wade desarmo (heelflip back smithed LA high rail, and did a heelflip back lip at da playground), i just think when your skating regular kickflips>heelflips