-Is BIM easier to use than CAD?
No. It is much harder, requiring good 3d perception, superior organization, deeper construction and design knowledge.
But is CAD really easier than BIM? I've extensively used both CAD (in the form of AutoCAD) and BIM (via Revit), so I consider myself qualified to attack this question.
First of all, I don't think that BIM requires good 3-D perception. A 3-D object-oriented software program allows the user to view a wall (or door or high rise apartment building) in 3-D (from any angle) or 2-D (any section, any elevation) immediately after placing it in 2-D.
Utilizing CAD, if I want another view of that wall after I draft it in 2-D, I have to draft that view. It seems like CAD requires more 3D perception than BIM.
I'm not exactly sure what Miguel means by "superior organization", but I'm just going to make a few assumptions and dispute the point. In BIM, the design is contained 1 file (where as CAD needs hundreds of files - usually 1 per 2-D document). In BIM, the documents are created directly from the 3D design, so they are already coordinated to a certain extent. Parametric change technology populates design changes to every 2-D document and view (2-D and 3-D alike). In CAD, design changes aren't included in the documents quite so automatically. From this, it seems that BIM is inherently more organized by the software, so doesn't require the user to have this sense of "superior organization".
To a certain extent, I suppose that BIM does require a greater knowledge of design and construction concepts and practices. In BIM, the user is actually building the building in 3D, rather than drafting it in 2D. I don't think that makes BIM more difficult, though. In fact, I found (working as a CAD drafter in an engineering firm) that I had a hard time creating 2D drawings and details of components that I didn't understand.
Lastly, I find that BIM software is much more intuitive than 2D CAD. Although I worked in CAD for about 4 years and became quite a proficient user, I am a much better, much more versatile and efficient Revit user after only 1 year.
Miguel, I look forward to seeing your qualms with this post - thank you in advance for your comments!