Just bought it, and I'm happy. Obviously its a mystery pack so not everything is "Usable" for the game I am making, but a lot of it is :)
Overall I give this a 8/10, I will likely buy your Humble pack in the future!
EDIT: I noticed the "GIFTS and rubber ducky" the models textures seem vibrant and colorful in the preview image but the actual textures provided seem extremely muted and almost tinted darker.