It means you will have to use a lot more coax to reach your radio unless you are on the high side of the sloper where the match box is. There is no real difference. If there is surrounding (metal especially) structure close to the match box that can have an effect. But for the most part there is no appreciable difference other than the amount of coax needed to reach the rig.
By for the most common method is to feed the antenna as close to the radio as you can.
Thanks for the reply. I’m also wondering if mounting the feedpoint at the bottom of the slope has a negative affect due to the angle that the different sections of the quad hang from the long wire. The angle for each element would be less than 90 degrees if fed from the bottom of the slope and greater if fed from the top. Would this matter?