I would imagine that both programs are needed for this process.

Also, I haven't read many complaints from Daz users who are unable to work with Poser stuff, but I have heard from many Poser users complaining about not being able to use Daz stuff...especially now that Poser 12 will be moving forward without a DSON importer.

Personally, I have recently purchased the SY Victoria 4 and Michael 4 body clones for Genesis 8 over at Daz for this exact purpose. To me It would seem prudent to have a way to use these assets outside of DS on a Poser native/flagship figure... all the rigging tools are waiting in Poser.