Thanks Rick. Went to that site that evening and got what I could as far as specs., yet they don't mention any info. on the supportive grid. Contacted local tech/sales rep. of HD and he wasn't quite sure what to say.
So, the end result is a 2x4 typical acoustical tile grid that is suspended above the HD finish grid that is classified as "supportive", it is suppose to be pencil tied for support. Conduit is attached to bottom of this grid, as well as all fixtures, and the HD finish grid. Purpose of top grid is to block out the mechanical ceiling above, the HD grid is just 2x2 open squares that have approximately 4"x4" squares open to all above. Hence the upper ceiling,one as structural, and two to close out all the mechanicals.
At this point, the AHJ has not come to convey his feelings as to whether it is supportive for all attachments, yet the design of the engineer states that this is a "supportive" structure for all attachments.
Being a new concept, it seems the jury is still out, everybody is use to the typical scenario of eveything is to be independently supported by it's own pencilwire.
So, tomorrow I am attaching all of my EMT and so forth to the bottom of the top grid, then to see what is going to happen.
Past record is some AHJ's say no and others have contacted the engineer to get the specs. to allow the new concept.