Another thing to consider is deer ducking the arrow. I would guess 40% of all the deer I shot with my Matthews ducked the string to some extent, especially when I "meh" to get them to stop.
Since my shoulder surgery and switch to Xbow, I would say 90% of the deer duck the string to some amount. That Xbow is MUCH faster than my old Matthews but its also a LOT louder. At deer camp there are a couple guys who believe that the Xbow is so fast the deer don't have time to duck the string. WAY too many slow motion videos of deer ducking the string not to believe it. My personal experience is that my entrance/exit is almost always a little off from how the deer was standing when the trigger is pulled. When you figure out the change in impact and or exit, the obvious answer is that the deer moved, usually down and twisted away from the noise.
This is another CON of shooting front on with an Xbow. They might not jump the string much, but it doesn't take much to go from a dead on kill shot to a long tracking job and or lost deer.