One thing that would help us out on the MEP side of things is, after placing a space and relying on the boundary objects to define it; let us modify the boundaries after the initial auto placement so that we can customize the space so that we can easily include the chase areas such as water closet chases and other smaller "sliver" spaces. This way we don't have to go into the Architectural bounding objects and toggle them off so when we create our spaces it bleeds into closets and other voids, which I am sure the Arch would not really be happy about. These spaces are critical to get accounted for especially in larger buildings when we are dealing with LEED certification!
This would really help us out before exporting to GBXML for Trace analysis. Yes we can modify sliver spaces in Trace...but give a an opportunity to easily take care of it in REVIT please!