Hello, Claywoman, welcome to Posetteforever, at last!
Posy, please cover you ears for a moment...good.
Clay, using any model too much can be boring and a problem in creating the character you need at the moment.
OK,
Posy, you can listen again.
So you can use any of a variety of models for the basis of your characters. As I use many different ones. My three favorite creations are Margo based on V3, Margo based on SP3,
and Virgina based on
Posette, wiht many extra morphs and with a new UV mapping.