G2Female is a different mesh than G1, so there is no direct cross-compatability between them out of the box, and yes it's gender specific albeit with zero improvement to genital representation.  Additionally, you cannot use V4 textures by default but can buy an add-on product that makes this possible.

G2Female uses DSON to get into Poser (sorry, I don't actually use Poser myself, so I don't know if the improvements claimed make a big difference or not)

G2V6 is still an improvement over the typical G1 female character, but is by no means a replacement.  If you don't do pin-up art and/or fantasy scenes with sacntily clad females, might be worth waiting until it's in the bargain bucket.

Dimension3D is working on an updated/new version of GenX and Sickleyield is working on an updated/new version of SRMS, so once these good folk do their thing, G2Female will become a whole lot better - including ability to apply G2 clothing and shapes to G1 (at least that's what they're trying to achieve at time of writing, don't know how successful the results will turn out to be, but should be ok).

As things stand, G2Female+V6 is a human female, not the blank canvas G1 is that can be made into any bipedal character (male, female, monster, alien, or anything in between).  G2 will give great results for female characters so long as one is prepared to pay for the new content that will be coming out for it.

For what it's worth, I've bought V6, but G1 will still be the workhorse for my characters in general.  I won't be buying everything that comes out for G2V6, but only the items I will use for definite.  I am not buying unnecessary items just to be a cash cow to DAZ or anybody else, but I do some pin-up art, so V6 does have its uses to me.

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