1. Sections and Elevation are generated as events in ADT and must be updated if any building changes are made
2. It does not read Revit files
3. It does not create a cohesive, single model file. The model is divided into separate files.
4. System requirements may exceed your current machine. Check to make sure you have the horsepower.
5. The learning curve is steeper than Revit (in my humble opinion)