Just wanted to wish you luck with changing the bed.
I changed DD cot to the toddler bed when she was 14 months and have had no troubles. It only took a few times of putting her back in the bed but she has never fallen out (I put a big sheep skin next to her cot just in case as a bit of a cushion). She seems so much happier now, I guess she likes not feeling restrained. I thought I was going to have troubles but she has been great.