Thanks to all for the honest replies.
As for breakage problems, my company (Dioramas Plus, see the ad to the right) has a pretty good track record. I've sold over a thousand items on that "auction site" & have a 100% rating w/zero complaints. I bubble wrap the castings strap them to two sheets of cardboard, wrap them with shrink wrap, wrap that with newsprint & them fit the whole unit into a sturdy cardboard box. Still though, if for any reason you end up with a damaged piece (even if it's your fault) give me a call & I'll send you a replacement piece at no charge.
As to whether hydrocal is simply too soft & that it might get broken after you have the diorama assembled, well, I guess that may be a double edged sword. The very thing that makes hydrocal attractive as a building material (ease of assembly, kitbashing and making modifications) can be a downside if you drop your finished diorama. Solution? Handle your finished diorama just as you would any other finished model. Don't drop it or handle it roughly. : )
Thanks again to all. I'm working on some new stuff w/bases now. Cheers.
Randy Pepprock
www.dioramasplus.com