Mel, I put DS1 in a bed at 20 months before DS2 was born, and we have had all sorts of issues getting him to stay in there to go to sleep and even now, over a year later, one of us needs to be near his room till he is asleep to keep putting him back to bed. (although it might only be once or twice now.)

I have bought another cot for this one, as I figure I can sell them when I am finished with them. I will be leaving DS2 in a cot as long as I can and have DS 3 in it's own cot.

But I agree, I think it depends on the child, and what suits you!