I've worked with a lot of designers over the last 20 years. A couple previously on 99designs, and many, many from 2d artists to sketch artists to 3d modelers to 2d and 3d animators.
This guy, NMN82, was one of the best. He's a great designer, but just as importantly he understands the language of design. He doesn't just give you something and say, "This is cool." He'll give you something and say, "I tried to create something cool by combining these elements which highlight X about your product in <this way>, and draw your eye to your branding in <this way>."
I really appreciate that kind of passion and thought around a craft or an art, and would definitely work with him again.