One of my course-mates at college in the UK had just come out of the legion. Very nice guy. He had, however, a presence about him that told you that he had a short fuse.
One of the guys building my house spent 3 months in the selection process before being turfed out. A couple of his friends who signed-up at the same time as him are still 'in'.
I know of a couple of guys but they wouldn't be friends, so I couldn't comment. I can recommend the book 'The Naked Soldier' - very good book basically a tell all of one guys life in the legion.
The Cork Man who was on George Hook was Padraig O'Keefe. He wrote about his experiences in the book The Hidden Soldier, it is a fascinating read. I used to know him in my youth. He joined the legion for a challenge and something different. He is a fairly "normal" guy.