I went into a creative mode game yesterday and played with all the bows fully perked, mainly to see why I hate crossbows so much and to see if they get any better.
I also wanted to see how well I could hit those headshots because this thread is not the first time I have heard this about the bows. For the most part, everything seemed fine. To me, there seems to be this one spot, though, where the neck meets the head (on either side) that I sometimes miss and from my point of view seems like it shouldn't have. Other than that, I don't seem to have any problems. For instance, I have never once seen an arrow just slide right through a head and keep going without impact.