Fibery is a promising app because of its interconnetivity of building blocks. However, currently (probably because of the focus of the developers) I find that the system is not very polished with regard to worflows and UX.
One main need I have after creating a structure, is to quickly create entities that I often use, with one click. In other tools, this is often possible through a simple menu, which allows for one-click creation of an entity of a particular type.