I would like something more original.
I don't really mind the price - I just think they should probably split the Pack into two DLCs (portraits and ship models) like they did for most CK2 cosmetic portraits. It would be even better if they added some music tracks. They could sell the portraits and the music for 2 euros each and the models for 5.
I also think it's a mistake to wish for a light gameplay DLC instead. If they are to release synthetic species with their own gameplay, they'll surely do it in a specific, full-priced, DLC, with new mechanics and all. Not in a cosmetic DLC - which would not be cosmetic anymore, by the way.
Something like "Exotic Forms of Life DLC" would be nice.
On the other hand, a Humanoids pack would be nice too, given how common they are in Science Fiction.