Simon Waddell wrote:

Christmas is a-comin' etc. and I'm thinking of replacing my old A14 diluter
demand system with a Mountain High EDS system.

Go for it, you'll love it!

One point: Theoretically, the cannula is even more efficient than a mask
- as long as you make sure you're breathing through the nose! (This is
the only reason why the manufactorer recommends a mask at altitude.)

Stefan