Sorry I didn't join in on this over the weekend, but my internet went down (made for a great weekend actually).
@ Ken: sorry for whatever happened with the support issue. If you need support and have trouble like that again just PM me here or post on http://forums.doublecad.com and I'll make sure you're taken care of. Sounds like you're happy with TC16. Your DC problems are odd though -- I haven't encountered them.
@ Linea: thanks for the compliments and support.
@Jim: regarding Xrefs, it is only one-way. You can't Xref the DoubleCAD file into SketchUp. But it is 2D CAD designed for documentation, so typically you wouldn't want to do that unless you wanted an elevation or something that you could bring into Layout for a presentation.
Also, creating an Xref is only in the PRO product. If you have an Xref in the drawing you can open it and update it in the free version, but can't create new Xrefs there.
I'm not sure that the Xrefs are the most powerful aspect at this time. We're adding a lot of functionality to them to make Xrefs more robust. I believe the "drafting palette" functionality that we've done in the PRO version is perhaps the best time saver. It is a feature normally found in MCAD products for sectioning and documenting mechanical parts, but we've taken the concept and extended it to surface models like .SKP for architectural elevations, floorplans, sections, and more.
Thanks for the thread here, and thanks for the interest. We really want to move rapidly in development, and are listening carefully to what people say, so thanks too for comments and feedback.
-- William