Overall, this is a great mattress. I really like that the entire shell can be unzipped and washed, especially the feature of unzipping it all or just the toddler side - probably my favorite feature. I also appreciate the shell being lined with water proof material on both sides. The only complaint I have is that there’s nothing on the mattress itself to help identify the infant side and the toddler side. Given that there’s not a huge difference between the firmness, it’s hard to tell which side is which. It took a couple nights to get used to it, but my child has since slept well on this mattress.