Here is what summiter Urs from Switzerland had to say: "Overall it was a great experience. Technically it was very easy. For competent off-piste mountain skiiers and snowboarders, I would recommend skis or split board over raquettes/snow shoes, as the way down is very breathtaking.
The challenge of Mustagata is certainly the altitude, rather than the technicality of the terrain. It's more challenging than easy two day or week-long climbs like Island Peak or Kilimanjaro."