I'm a little late to the party but figured I'd throw my 2 cents in. I work for a general contractor, and we implement Revit on nearly every project (among other 3D software). We typically have modeled our own architectural model off the 2D CD's (either the architect didn't model or they modeled only a design model for their internal use). But there are a handful of projects where the architect has modeled, and shared, their Revit models as well as maintained them through the life of the project. I can't tell you how much I prefer the latter .
There are still other separate models for construction and coordination such as civil, steel, foundations, and M&E. Those aren't all done in Revit though. Steel might be Revit for CD's but not for fabrication, that's usually done in Tekla. Our M&E subs prefer AutoCad MEP vs Revit MEP. We tend to use Revit along with several other programs for a multitude of purposes.