I still use V3 , for some reasons.
First:    
She is the figure i have the most stuff from the stores.
Second:
She works in my splitted runtime environment without problems and does not
fill my harddisk whith useless crap.
For example:  My custom V3 SAEc.cr2 File has 1.458 KB of space.
its possible it inject and remove any single morph i need.

I got V4 and the Morphs++ Pack from Daz what means 2 files:
Victoria 4 Base.cr2    7.669 KB    the base with Expression Morhps
Victoria 4.cr2        36.618 KB  The full version with all Morhps
and not a single Injection File to Inj/rem any Morph.

Boah ! 36Megs for each .pz3 or .cr is save ...
Use file compressions, ok , its still a lot.

I bought some products for V4  and did some tests.
On my opinion V4 felt much more 'plastic' than V3 that time.
(Well looking the renders in the galleries now, this has changed i think)

Later i updated on the Daz Page to V4.2
She doesnt like to be installed in her own runtime, (e.g. D:_RTV4)
no this lady has be installed inside your mainruntime, means the poserinstallatoin itself
(e.g.: D:P7)
otherwise you get a lot of errormessages loading her.
On that point i stopped with V4.2.
I event dont rember wether V42. brought inj / rem files.
(mybe i deal with this in the future)

Besides that i discovered that Jessi form P6 is nice too.

greetings
xuu4u