Catherine, along with Monte and Shaka, are on my kill on sight list if they happen to be near my start. Been backstabbed way too often. Izzy can be fine if you happen to share her religion. Bit of a problem if she doesn't spread it to you. Last night, I started between Catherine and Izzy. I opened bordered early with, had confusionism and state religion, but never got a single buddhist city. While I was storming St. Pete, Izzy declares on me. I vasselled Catherine, but couldn't shake Izzy for the rest of the game. Solid wall of war from about 500 AD till 1923, with a small 10 turn period of peace. The biggest problem with her is that she seems to always be able to vassel and medium sized power early (who vasselizes without apparently losing too many cities), and she and her vassel become huge pains.
