Mine are vastly different in personality, as well., but they aren't related to each other. My boy is a very well-bred F3 and thinks he's above it all, very regal. My girl is a rescue from a hoarding situation, not well-bred and has the health issues that go along with it. She is a little kleptomaniac; she steals things (weird, non-cat items, lol) from all over the house and hides them in her "stash" under my bed. I love them, and my other two, with all my heart, they are all my spoiled babies, and they certainly keep life interesting!
Definitely going to try the Special Kitty, thank you for the info!!!