Another thing which is a factor on some A/C like a PA-28 is. Say your stall warner is inop. You over rotate with 25 / 40 degree of flap, The Turbulent Air Flow is deflected by the flap away from the elevator, hense you do not get a buffet as a stall warning + the a/c stalls at a Low nose Attitude, that one has got a few people. A good demo with an instructor is, at a safe Alt for stalling, pull the stall warner breaker, Simulate a go-around at height and then over rotate with 40 flap. Height loss will be 300ft +.- Make sure to reset the breaker.