The same things you are saying now were said by others for V3, V2, etc.  

When a new model is released there is a limited number of add-ons for it, such as textures, custom character morphs, etc.   No matter how many morphs you manipulate on a model if 100 people are all using the same texture in 100 renders, you're bound to find similarities.   I'd say give it time and you'll begin to see how different she can look.  

As for that lifeless look, it's up to the artist to make use of the tools available to change that.  V4 has, IMO, the best expression morphs of all the DAZ characters so far.  I like the her porportions, not like pinhead V3 - I always used to scale her head to 104-105%.  But I don't like her eyes and tend to scale those down - if everyone used all meshes as they are it would truly be boring, so don't be afraid of modifying according to your own tastes.

Here are a couple of examples how the standard textures that come with V4 can be changed to give her a different look.  I've added other eyebrows on the texture itself and a blush layer in the material room.   Not that I believe these warrant a five star+ rating but they do portray her a bit differently from what you might see out-of-the-box.

Ultimately, the choice will be yours if you NEED or WANT another female model.   I can never resist the new and usually get almost all human/toon meshes :)  And, hey, I'm not getting any percentage so I really have no vested interest in persuading you to buy :D

Oh, and please click on the image, these boards really do make a mess of compressing.