Another point - full range of motion = full development. How many other exercises do you see people doing with only half the range of motion? Okay so somtimes they are done by bodybuilders wanting to concentrate on aesthetics, but its not recommended as the norm. In gerneral we are told to use FULL ROM on our exercises as this recruites the most fibers and thus gives the best development. Most people with truly impressive leg development are in fact full squatters, or atleast to below parallel. Obviously there will be exceptions to the rule and there will be people who have only ever squatted 1/4 squats with big quads etc etc... but as a rule of thumb....
just my 2p worth