The "I" in BIM is the defining factor of what makes a software a true BIM application. Any software that allows you to attach, store, and extract information from a model (whether 2D or 3D), and allows you to present design intent and investigate constructability, goes a long way towards implementing BIM and Integrated Project Delivery. (Notice, I'm not saying that a software is BIM. I'm just saying that it is a tool to help you create BIM and integrate your processes with the processes of other. OK, rant over.)
Given that, I wonder why Autodesk chooses to market its products the way that they do. Revit Architecture (RAC) is the flagship BIM platform in Autodesk's armada of software. AutoCAD Acrhitecture (ACA) is billed as a tool designed to increase the productivity of "Architects who know AutoCAD." No mention is given in the advertising literature about ACA's use for BIM.
Alot is said about Revit's ability to attach parameters (information) to elements in the model and schedule them out. ACA has similar ability. ACA let's you use a ubiquitous file format (.dwg)(remember, interoperability is KEY in Integrated Practice) to produce a 3d model that uses "smart objects" to represent and document the built environment. These objects "know" what they are and how they should interact with objects around them. Doors "know" that they go in walls, as do windows. Roofs are modeled based on complex rules running behind the scenes with limited input from the user. These objects also have information attached to them (manufacturer, material, etc, etc.) and they can communicate that information to schedules created within the program.
I DON'T think that ACA is as robust as RAC in some functions. Sections and elevations aren't "live" you can't select objects in them and modify those objects. When you make changes to plan views, you must update the section or elevation that is produced from them (which could lead to uncoordinated documents.) You can't select objects in schedules and make changes to them that effect the model.
However, all said, ACA is a pretty darn powerful modeling, drafting and information organizing software. Wow, sounds like BIM to me. It is especially useful in leveraging the training and skills of users who are experienced in AutoCAD.
I'd love to hear the opinions of anyone who has used ACA or by its former moniker ADT Architectural Desktop (either in a BIM capacity or not) on real life projects.