Well, if someone wants to use Dexcom sensors, there is no advantage to using the MM pump instead of the X2. At least no compelling reason that comes to my mind.
EDIT: Actually, there IS a compelling reason–when one’s pump breaks and you call for a replacement, but Tandem can’t get it’s act together for far too long, so you end up contacting Medtronic which ships out a loaner pump in 2 HOURS and in a few weeks you get a perfectly acceptable pump, the 670G. Having said that, I’ve no intention of using Auto Mode, or MM sensors. I’m glad that Tandem dropped the ball.