I have taken the straight down spine shot 3 times and harvested all 3 animals, right at the bottom of my tree. I have practiced this same shot 1000 times in my yard. The results on the spine shot have all been the same, through the spine all have either hit the heart or major vessels near it and my broadhead came through the chest plate twice and once just the tip poked through.

I have not nor do I practice the front facing shot, so I would not even consider taking it.

Everyone has their opinions on what is an ethical shot. For me, it is simple, any shot that I absolutely know when I release the arrow will result in a humanely killed deer.