I just started using VW about a week and a half ago. Took me a long time to wrap my head around DLVP. Once I did, I saw why it is so awesome and time saving. I went and built a show using this method, then tried to export to MA3d. Didn't work and I realized why.
I actually went ahead and build everything in my show in 3D space. Everything has gone semi smooth as far as importing objects. Draw backs I can see, 2D plots will need to be thought about. Moving things is kind of a drag, I group stuff to help. The DLVP is really easy to move my stuff easily and as one piece.
Found a work around to the multi-instance fixtures. Just import some random multi-instance fixture and change it in the fixture types menu in MA.