Since it mostly peaks that push to 14K, its more likely that you'd be camping/cooking at something more like 12K.  But the MSR XGK EX is actually listed as the high-altitude version of their stove.  In reality, it is the same burner and they have run a portion of the fuel feed line over the top of the burner to pre-heat the fuel before it gets to the burner.  However, you can achieve much of the same effect with the DragonFly by using the wind screen, even when its not windy.  It will help reflect heat back toward the burner assembly which will also help warm the fuel.  Another advantage of using the wind screen is that you can conserve fuel because less heat gets dissipated via air movement.  The effect improve dramatically if your pot just fits inside the wind screen.  The MSR 2 liter titanium pot is just about perfect for this (but also pricey).  It has the additional advantages of quick heat transfer and light weight.  One downside is that it transfer heat so quickly that food will have a tendency to scorch on the bottom of the pot if you don't stir with some frequency.

dd