All 30 positions are loaded, so the circuit count on your BOM needs to match exactly. The push-pull fastening means it's a friction-fit mate; there's no latch, so it's suited for internal board connections where the assembly won't see high vibration or cable strain.
Gold buys you corrosion resistance for moderate mating cycles and environments where the board might see humidity or light industrial exposure. The phosphor bronze contacts give good spring retention over repeated insertions.
