I've brought this up before, and they work very well the last time I used Autocad, v.2001 or 2002? I think the only thing it was missing was it did not reposition the drawing window like our GTV's do, which is not a big deal at all. It sure would save a lot of work exporting files to DWG. We wouldn't have to do Layers On, hardly at all if this could be figured out. Even if our GTV's could not be created in the dwg files when exported, if our GTV's could be exported as external layer states, then Autocad users could just import the states they want to use. Either way it would be a
huge feature I'm sure for us Datacad users in working with Autocad clients. I created a little example file to send along with our DWG files for those who didn't know what they were in hope that A) they would start to use them and B) that maybe it would help those Autocad users who leave a rats nest of data scattered all over their dwg files would learn how layers can really be used well.
Here is a scanned PDF of part of that document. I don't have the original anymore I guess