These are just subjective impressions, I have no hard data.

Q: [Genesis figures] Have these replaced v4 and m4 for most people?

A: I get the impression most people are still using V4, M4, Antonia, and other figures designed for Poser. As I understand it Genesis is not compatible with Poser.

Q: Would you guys say the majority of the community is still using Poser primarily or have people trended towards Daz Studio now.

A: I get the impression that only a small percentage use D|S. But to be fair, I'm a Poser user, and this is the Poser forum. If I hung out in the D|S forum, perhaps I would get the impression that quite a few were using D|S.