Is this thread dead? When searching for a new radio, it's been an interesting read.
I noticed most of the discussion was to orient an antenna sideways or vertical, but there is not much mention of vertical down. This is probably because most radios don't allow it (and I'm not sure why). If the antenna is pointed 45 down toward the dirt directly in front of you, then you will never be in the cone of silence. (Unless you fly directly behind your head, or 200 feet below the dirt).

Understanding that a common response is "I've never had a problem" this doesn't necessarily mean the signal radiation is optimized for best quality.

There are only a couple I've seen that allow the 2.4 antenna to be pointed downward while holding the TX flat. Even within the same brand, there are differences. I can tell you that for giant scalel aerobatics, a right pointing antenna will put your plane in the most inefficient RF footprint when you are holding your body parallel to the flightline with the plane on the far right side of the aerobatic box coming down from a maneuver.

-DJ