I have Z-Brush 2 and 3, but I never ever missed a single of their features since I really started to use the morphbrush to it's full potential.

There is:
push/screen
push/surface
pull/screen
pull/surface
smooth/screen
smooth/surface

There are several brush sizes with the smallest making it even possible to move a single vertice.
And an unlimited amount of brush strenghts avalable just by spinning a dial.

What else could I need to morph a Poser figure ?
Yes, morphing across groups would be nice, but for now I don't complain about the workarounds.

Sure, when you do "free" sculpting and start with a gazillion polygon hi-rez sphere, all those other super special ZBrush morphing tools might become handy, but the original poster was asking about character morphs for Poser meshes.

And for that I feel that the P7 morphbrush is more than complete because the maximum polygon size of a typical Poser mesh is quite limited anyway, so even if P7 had all those additional sculpting brushes, you wouldn't be able to properly use them anyway.

I also feel that the ability to work with a fully textured figure or object directly in Poser in "real time" is much easier and inspiring for me, especially for face morphs.
I don't have to guess how the result will look in Poser, because I can actually see it while I'm sculpting.

ZBrush is especially useless to create new or to improve default expression morphs for Poser meshes.
With the morphbrush, this is no problem anymore.
I dial the expression with the default morphs to get a starting point and then modify it with the morphbrush untill it looks like I want and then just safe it as a new morph.

With the morphbrush, I can go backward and forward, play with ideas, do minor changes, undo them, look at the object under actual Poser lights, spawn different morphs, recombine them, all a lot easier and elegant and more efficient than the constant exporting and testing needed with an outside app like ZBrush.

And it's ability to re-sculpt joints lets me finally get that kind of realism I always wanted when looking at "professional" weightmapped charcters, but never was able to achive due to Posers "primitive" joint system.
Now it's actually the other way round:
I can make joints look any way I want and now weightmapping is the "primitive"  rigging system in my opinion.

So while ZBrush is a fantastic sculpting tool, to really improve Poser meshes, it's way to limited for my taste.