Depends is the correct answer.
As a guide I would start lower and over time work you way up (not the same show). Find what height you like the sound for a particular room and use that, I would also not always assume that the other tapers having theirs at a height is correct. Determine the conditions as follows:
Bass (low frequency) are long waves, they take a longer time to disperse. If you are taping close and have the stand high the bass will be lessened. This is why the Navy uses extremely low frequency to communicate with submariines. Low frequency waves disperse less than high frequency. Over distance low frequency gets lost in the other sound and is more susceptible to waves bouncing back from the walls and other objects in a room. That is why you hear the thump thump thump of that guy in the car coming at you until he gets close and you hear the other sounds coming from his car.
Too low and you get crowd chatter, closer proximity = louder sound.
I taped the cheese a few years back at the pier in San Diego, all the other tapers had their stands high, I kept mine low. Others later told me my tape sounded much better. Why? Well there was a slight breeze up higher, this caused the sound to have that in/out affect, down lower the stage blocked the wind.
You really need to observe the taping condition and base your setting on room, crowd, wind (or A/C, ceiling fans, etc.), distance from sound system, distance between bass and highs of the sound system, amount of insulation on walls (slapback), and a whole lot of other factors.
So as I started with; DEPENDS!