I night-weaned and used the CIO approach with my first. My second one night-weaned at the same time we were moving, and because of logistics, he and his brother slept together in a bed. When we got to our new house, they shared a room with single beds shaped in an "L". I had the same night time routine as always - baths, quiet play in their bedroom, reading, and turning out the lights. I never had trouble at all with this.
The only problem I had was when I was pregnant with my second and laid down with my first child during my first trimester. I was SO tired and I'd conk out with the book. My son got used to me doing that and when I stopped, he started screaming about it, and then waking in the middle of the night trying to come into bed with us. This was totally new. I could NOT go back to sleep in the middle of the night after being woken during my second pregnancy. I was working full time and beyond tired. I would NOT allow him in our bed and I became Darth Vadar to get him back in his room. He slept in his floor a little, but once he knew I meant business, he went back to his bed (it was a lot more comfortable than the floor.) We never had sleeptime issues after that, ever again.