This is perfect for my toddler because it is so low. He loves climbing up and down the ladders and became agile at it quickly. 6 inch mattress is ideal for the railing. We love everything except the packaging. The assembly was easy, but the packaging/delivery. The box was far too heavy (team required, per the box instructions), but was delivered by one man (naturally). I have no idea how one man dragged it up to the front step, but kudos to him. The box was ripped open quite a bit.