Alright. If I remember correctly, until recent expansions, there was only one tier of Headshot that could be trained in, correct? My question is: I'm going to assume it's dexterity that affects your chance to land a headshot. I'm currently using (I believe?) a Stonewood on my Ranger. I have gotten like 3 headshots in about 4 months... and I do a lot of killing in Acrylia (the entrance mobs, I can headshot at 65, I do believe), and even decided to run through Neriak and kill all of the guards one day, out of boredom. I got 1 headshot after about 3 clearings of Neriak.
I know the Stonewood is a bloody slow bow, but shouldn't I, with 285 unbuffed Dex, be landing headshots a bit more often than that?