Modeling your project during the conceptual design can drive the most benefit during the "pre-schematic, post-pre-design" stage. Unfortunately this is usually not a time I a project when much attention is being paid to a 3D digital model. When you model conceptually you can gain a deeper understanding of your project without spending abundant hours developing any single idea. Massing tools are how we model iteratively without weighing our ideas down with detail.
Not all massing tools are created equal. Sketchup is great for quick modeling and visualization but the data behind the model isn't there and the downstream use of those objects in analysis and documentation in Revit is very limited. There are some tools that allow you to analyze inside of Sketchup, the IES toolkits have a plug-in for Sketchup, but I can't do anything with these models later on. More often than not designers misuse Sketchup by creating detailed forms just to get an image. This wastes hours on a project without creating anything to leverage later on. Models in Rhino usually suffer the same fate.
The massing tools inside of Revit can be used to create a 3D generic form that allow schedulable parameters of surface area, volume, perimeter by floor, and area by floor or building. These can also be used for high quality renderings via FBX export into 3DS Max Design, or as rapid energy models for comparative analysis. Exporting the mass model GbXML file also opens up many other analysis options in outside software. Autodesk Labs' Project Vasari expands on this even more with solar radiation and wind tunnel studies using mass models directly inside of a Revit-style interface.
The beauty of these types of massing studies is that they are quick and provide a lot of good comparative data. The key word there is 'comparative'. Model multiple options, then compare, to understand and proceed with your design.