I’m an architect who has used AutoCAD since 1984 (version 1.7) and its architectural addons since 2000. Looking for a supplementary program to quickly create more “architect-y” looking images and drawings particularly for the design phases, I bought SU5 in 2006 from @last an hour or so into the, I think, 8 hour trial. Every time I use it I remember the joy I felt as I navigated smoothly around a model I had imported from AutoCAD and quickly applied materials, marveling at the shadows and transparencies and how SU automatically got the shingle textures oriented properly on sloped roof planes.
On the other hand, trying to hatch the walls of an SU floor plan view with different materials and shadings (brick, concrete, non-bearing frame wall, bearing frame wall, etc.) is, in comparison to even early AutoCAD versions, horrible. Paint wall bottoms or a SectionCutFace face with a raster hatch pattern? Buy an add-on? Don’t think so. I’m not going to fiddle around with Layout manual dimensions when I can click onto a wall object and have an associative multi-chain dimension pop into place that dimensions the wall as well as the locations of doors and windows in it.
There’s no way I could work without either of them. Each of them have tools I see no reason to do without. The fact that Layout exports PDFs (vector, hybrid and/or raster) and I can PDFATTACH them in AutoCAD/ACA means I can use the best features of both throughout a project.
Every programming language I know has both AND and OR logical operators. I can’t think of why the result of a AutoCad/Vectorworks/Revit OR SU/Layout comparison is inherently better than one of AutoCad/Vectorworks/Revit AND SU/Layout.