This is perfect for my 4 year old twins! It was very easy to put together and it feels quite sturdy! It also holds quite a few books in all different sizes. 
I love that the height of the book rack is just right for them, they are able to help themselves to the books they want to read independently.
I think this book rack will last us for as long as we will need it. I would definitely recommend it to someone with small children who are starting to build their book collection.