Multiple microphones for EQ certainly aren't snake oil, as the idea of sampling more than one location is a pretty widely used one. Lexicon uses it on their MC-12 (connections for four microphones if I remember correctly) and Audyssey's MultEQ can do something similar (one mic, moved from place to place), to name just two examples that come to mind. I haven't used the MIC-5, but I don't doubt that it can provide benefits when setting up the SMS-1 for a space with multiple seating positions.