...well, if you want your turret to be able to rotate around like that girl's head in 'The Exorcist' , then leave your turret 'upwards'.....but strangely enough I find mine rotates as much as needed 'upside down'. Remember, the turret rotation capacity only needs to provide a little bit of 'play' in the system.....that turret isn't going to move very much as it's pretty much locked in place by all the hoses sprouting from the 1st stage, and the fact that the BC hose is also attached to the turret, and the business end of the BC hose is attached to a fixed attachment point which is gonna prevent much in the way of rotation anyway.
But agreed, it's a free country, do whatever floats yer boat.........