Nape (back of the neck).
I think they're cool and convenient for a bunch of reasons:
1. They're not as common as most other piercings, so people will be impressed how alternative you are.
2. They're easily concealed for times when you need to look professional (job interviews/meetings clients etc...)
3. They look cool
1. You need to make sure the bar fits correctly otherwise it pokes out and looks weird.
2. Because that part of your body moves around a lot, they can take a while to heal and have a high rate of infection and flare ups (especially when not looked after properly)
3. When you first get it done and it's still healing, you will catch it when taking your shirt off etc... That will hurt.
