Quoting LeTs*StArT*a*RiOt!:" Not all kids are the same. DD climbed her crib and pack and play at 12 months. She scaled it like a ... [snip!] ... is 15 months. As long as he's blocked to go to JUST his room and his toys, there's nothing wrong with using the toddler bed. "
This is true, and there are gates you can get that they cant climb. I have this one, and DS cant climb it.
He has been trying since we got it months ago lol. I also love that is opens, so you dont ever have to take it down, or climb over.