If you think he'd go back in the cot now I'd do it too. Annabel is the same age and she's been in a bed since Christmas, and it was too early. The only reason we switched to a bed was because we were staying with my in laws for nearly 3 weeks, they don't have a cot and she was getting too big to comfortably sleep in a travel cot for more than a couple of nights. She did great in it at first, but then it went a bit downhill. When she was in a cot she would stay in there and talk/play/sing to herself for a while after she woke up, now the second her eyes open she's out of bed no matter what time it is. This includes NWs! Most of the time we just put her back in bed and she goes back to sleep so it's not too bad, but it's disturbances that we didn't use to have. And sometimes we've had to do multiple trips back to bed. I would put her back in a cot if we could, but at this point I know she can and would climb out. Not sure if it's temperament or age... DD1 was nearly 3 when we switched her to a bed and we had no problems. So she was older, but has always been a better sleeper and a bit more mellow than DD2.