A monolith!
Need min. 240cm/8' ceilings for top bed to be viable. Looks good but will overpower a small room. I pinned the base under my sofa, rather than drill the wall. Platforms are quite heavy & long, so liable to tip if you don't anchor it somehow. Slightly thicker tube walls would be good - they can dent if you push on them too much during construction. Sturdy overall though. My BSHs don't climb or scratch it, but they do use all three beds (they use my cat wall shelves to get in and out!).