I think you're right that Decimator is pretty much what Poly Cruncher is but inside DS. Curious who they licensed it from.

And like Poly Cruncher, I've been aware it existed for some time.  The store page doesn't go into much explanation, but found a video by Jay Versluis (WP Guru) that does, and that it does much more that reduce geometry count.

Explains a great deal of above questions since it's non destructive & let's you create custom add'l LOD's.

Thanks.