My first reaction to introduce the concept of the diaphragm was the manual approach, similar to the concept introduced with the software sap80,
after its introduction and comparison of its results with the STAADPRO, ETABS, SAP2000, I would note that the results were not similar.
but the introduction of the concept of the diaphragm with "membrane" specified by the robot fights, we find the same results of "dynamic analysis.
I hope Autodesk won't spoil it. Since their having bought Robot from RoboBAT, they did absolutely nothing to improve the software.
The Robot's strongest point is the very convenient user interface. I would recommend it for all FEA tasks, and it is especially suitable for steel design.