I use both MaterialIQ and Extreme PBR in my workflow and I can attest to them being very much worth the price. Extreme PBR has more of a focus on rougher more natural looking materials including a lot of different wear stages for your various materials that can be layered for variety while MaterialIQ is more like the types of materials you would use for product design, archvis, and motion graphics where you want your materials to be clean, poppy, and brand new.looking.