I wonder how it would work for one that peferes to use an older version of DS how will he be able to get a purchased product from Daz latest version into an older one he needs to use, when I work with poser I use P6 up all the way to the latest version and also using different Library setups to work on the Files not one combined librarie meaning that files have to be installed individually for every work

Yup, that's a problem too (I still prefer 4.5, and I'd use non-beta newer versions were it possible to have two versions of DAZ on the same computer). Also not compatible with DSON since no version of Poser can read encrypted files. So unlike what MaleM3dia said, it's not just a minor inconvenience to workflow. Genesis 3 may be entirely incompatible with Poser, but the new props sold at DAZ are not, not to mention that some of the encrypted products are for Genesis 2, which IS compatible with Poser.