Nothing is cleaner than a simple floating shelf. The problem is, however, attaching a shelf to the wall with no support underneath (i.e. the floating part) inherently will make it difficult to bear any load. This especially applies to most of the pre-fab floating shelf kits, which are basically thin MDF boxes that sag with any sort of weight. And unless you don’t care about exact placement of the shelf (which you do), chances are you won’t be lucky enough to have more than one mounting hole fall on a stud.
After trying multiple different cheap floating shelf kits, Becki and I got fed up and decided to design and build our own. After all, the concept of a floating shelf is pretty straight forward: it consists of a mounting bracket and shelf/cover that slides over the bracket.