Even the exposed eastern coastline of Greenland in March is too warm to test this bag to its limits. Comfortably rated to -27 degrees celsius (on Rab's unique 'sleep limit' assessment) and favoured by alpinists upto 8000 metres, we had thought the arctic would give the Andes 1000 a run for its money. Not a chance. Combined with a synthetically insulated self inflating mat from Exped and a busy basecamp tent, I didn't feel the slightest chill all night.
Perhaps it may be overkill - particularly at 1625 grams - for low-altitude, sub-arctic expeditions, but that's a risk for the individual to weigh up. From my cosy cocoon I was happy with my choice.
Rab have packed 1000 grams of 800 fill power European goose down into the well-thought-out baffles of the Andes bag, then wrapped the whole package in Pertex Endurance to beef up the durability. This is high-end sleeping, and the price reflects that.
The design of the baffles, particularly around the foot box, keeps the feathers where they should be, and the hood is particularly pleasing - close-fitting when necessary, but surprisingly unobtrusive in warmer environs.
It was the roominess that really sealed the deal in terms of comfort. Most cold-weather sleeping bags feel restrictive, and no doubt that helps with weight and pack size (aswell as insulation) but the extra breathing space here makes for a great night's sleep.
Another nice touch is the storage bag - made from some kind of linen or light canvas, which will last much longer than the snaggable mesh/net bags that most companies supply, and is another indication of how well designed and delivered the Andes 1000 is.