I think it all depends on what your needs are.

Obviously Poser has some major features that Daz|Studio doesn't.

Also Daz|Studio has features that Poser doesn't.

I have seen posts where some people have been using poser for a long time, switch to using Daz because of the easier interface or rendering.

I don't use Daz. I have opened it an have tried to figure it out but it's way too complicated looking.  I don't do well learning new programs.

I do know that if you ever download something that was created in a "newer" version of the Daz program, that you have to redownload the program and reinstall it each time.  The one time I tried to use it to convert something to an .obj file for someone and had problems with the props, it was a total PITA having to keep redownloading and reinstalling the program everytime the creator gave me a new file to try. I haven't touched it since.  I would uninstall it except for some reason Bryce calls on the files or something.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi