Jeff's a great guy, very very chill and he's always smiling and in a good mood when he isn't onstage. I remember he hung out outside the venue talking with me and my friends for like 20-30 minutes before a show two years ago, apparently he has mad 12-string bass skills haha.
I've got to meet a few 'big' guys I guess now, but I've only gone total fanboy a few times. The first time was when I talked to Chuck Billy like three years ago, and the second time was when I chatted with Tom Hunting a year ago. After doing a bunch of interviews and stuff, it's hard to see a lot of these guys as anything more than just regular dudes.
I would probably lose my shit if I ever met Rob Halford or Glenn Tipton though.