Yes, DS is 'free', but DAZ are 'content sellers', their figures are expensive. Think free shaving handles but pricey disposable blades. Yes, you can find lots of freebies there if you watch like a cat, but most are add-ons to add-ons to $$ purchases. And, too many of their budget items come with 'gotchas', like their discounted legacy products that say 'templates available', but don't due age of model and/or forum culls. Oops...

There are many DS freebies etc here at Rendo', over at eg SCG, EE and the like, but...

I began with Poser_3 'free' off a mag's cover-disk, bought #4, was moving to #7 when a multi-HDD disaster and family priorities took me out for almost a decade. Got discounted #10, soon moved to #11. The legacy of previous owners' neglect was glaringly obvious: There's still UI bugs & quirks I remember un-fondly from #4...

IMHO, Rendo' are doing the best they can to untangle the many, deep legacy issues, drag Poser " kickin' & screamin'  " into contention with Unity, XNA/Lara etc etc. I reckon DAZ is determined to move away from Poser-compatibility, and each generation of 'Genesis' makes it worse.

Two things:
When Poser gets 'Unimesh' working, which will be no small feat (*), that opens a window to 'modern' rigging. Then, eg FBX figures may become truly inter-operable.

I've found an easy route from rigged XPS to FBX via free Noesis. It usually 'plays well-ish' with Poser_11. Is there such from MMD's rigged PMX without a total re-build ??

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*) Long ago and far away, I used to code '6502' for fun, wrote robust 'utility' software for my lab in several BASICs. A wary amateur, I knew my limits, crafted 'clean code'...