Thank you, MinusTheBear, for that very useful post.
The reason I'm looking for behind-the-neck headphones is because I have a tendency to touch/scratch the top of my head, causing some hair loss. I used to use normal headphones, and often when taking them off, my hair would get caught in them and get pulled out. Also, I wear headphones for long periods of time every day, and the weight from larger headphones would weigh down my hair, which I'm not too sure is a problem or not. I'm just trying to avoid more hairloss.
You do have me tempted though. The Audio Technica ATH-AD700 I read on the reviews don't fit smaller heads, though? I have a smaller-medium sized head, so it probably wouldn't fit me very well, huh? Also, since it's so big, I'd imagine it is very heavy and weigh down my hair more than headphones I've had in the past?