I've been using BTC for a while. I've been using it at exchanges, to trade altcoins and to order goods over the Internet, but I've never exchanged BTC with someone in front of me. At a store or between friends, or family. This despite having had long conversations about BTC with various kinds of people, and attending a few meetups.
Who has exchanged BTC F2F?
In my own opinion, selling a huge amount of cryptocurrency is very dangerous if you did not know about the person you are having transaction with, the best thing to do is just use a reliable exchanger in order to have a safer deal.