The new G8.1 was underwhelming and I don't use it much, but the expressions work so much better than G8.
I had this character as a genesis 8 character and "converted" it to 8.1 by saving it as a Shape Preset and applying it to the 8.1 base figure. Is that the way I should be doing it? Seemed to work.
Yeh there's been a huge discussion about that on the Daz forums. Fortunately my favourite G8 expressions still work perfectly on 8.1. Maybe someone can tell us why some work and some don't.