Coopshin Hawk (Sharper's Perhaps)

I've been a bird nerd for many years now, but for the life of me Sharp-Shinned vs. Cooper's still makes me foam at the mouth. From this moment onward I'm creating my own species (we seem to be living in an era of personal reality creating anyway). Which do you prefer, Coopshinned or Sharper's? Joking aside, anyone got any tricks to reliably tell them apart??

 

Brown Acres - Jackson County - Southern Oregon

Done