Thanks for your comment.

Regarding the metal issue:
Please look at our chair from that pack! The leather parts of the chair and the metal legs have some specularity but the textile for the seating area does not. You also will not see any rusty part shine in our screenshots.
A good designer can control with a good shader via a specularity map what parts shine and what not. Every texture and model from the recently made packs comes with additional textures to control this.

I am planning to release a machinery pack very soon. After that it will become more complex: vehicles, characters, detailled weapons or fantasy architecture. I will probably ask our customers and will make some polls to see what people want to have.