We do a progression of all these. Normal sparring night is continuous med. contact sparring. All contact allowed except sweeps to the front of the leg/knee and no face... head is all good. As you gain some experience the instructors will let the higher belts or lower belts with good technique to go harder and face allowed if mutually agreed by the two fighting.
At our toureys is point stop for all color belts. So, we do sometime train that in sparring class, but not much. Black belt tourney is continuous point for 3-5 minutes depending on how GM feels about the crop of would be's fighting. Black belts are allowed to mix it up at their discretion. We're all brothers after all. Only strikes to the knees or back of the head or groin are really out of bounds for obvious reasons.
There are no PERFECT techniques, only perfect execution for the situation at hand.