This style of bunk bed we purchased for our 2 and 4 year old girls.  The little one is just about fully potty trained and it was important that there was a safe way to get down at night so she could make it to the potty.  Apart from a few frustrating hiccups with the instructions and the help of my in-laws we took 2 days to put this together.  (We needed a break.)
Our girls love it!  We like that it is sturdy and made of solid wood. Also that the top bunk is lower so that we can reach the kids/lay them down up there when they fall asleep.  I thought the clearance of the lower bunk would bother me, but it’s plenty for a  Little.  I could sleep down there comfortably.  The bunks give us more floor space in their little room and we’re all happy with it.