We did a bit of a modified version.

We were co-sleeping with DD, but in the months leading up to DS1's birth, we put a single bed right up next to our queen bed. We thought that DD would sleep there, but DH usually ended up there! By the time DS1 arrived, DD was sleeping in the single bed. She was still right next to me. DS1 was between me and DH (in the Queen bed). When DS1 was a few weeks old, we rearranged our bedroom and DD's bed was moved to the other side of the room. It was lovely to still have her close though. When she was 3 (DS1 was 6 months), she asked if she could sleep in her room (the room where we kept all her clothes and toys). She transitioned to her own room so easily, no dramas at all. She was ready and I felt so happy that we had not forced her to sleep independently before she was ready.