The bottom USB port as opposed to the micro USB port on the left side of the remote controller? I like to use the USB port since I have more USB cables, so the cable is not coming out of the side of the remote controller (which can get in the way), and since it's not as fragile as the micro USB port.
Exactly. @Thunderdrones, one of our resident repair techs (for those who don't know), created a post recently showing just how fragile the side USB port is; stating that he has had to replace many of them that have failed. Since the side port is the only port through which you can charge the controller, save it by linking through the bottom port when flying, to help preserve the side port for charging.