Hey all,
Some interesting (and valid) points you raise Joomy, so will go into a little bit of my thinking behind trying this sleeping bag. Firstly, I am not what you would describe as a Macpac brand loyalist, although I have a few pieces of their gear that I do quite like.
You mention some nice sleeping bags in you post, specifically the WM Antelope I like the look of a lot. At first I was keen on the sea to summit sleeping bags, traverse and talus series, but when I tested them I found the regular size too short (i'm exactly 6'), and the long too long - my feet weren't in the footbox, so i decided to leave them out. I am not sure with the western mountaineering bags which size would be best for me, and we don't have a supplier in NZ where I can try them. They sure look nicely built though, and from all accounts their ratings are an accurate reflection of the capability of the bag. I suspect these ratings are based more on real world performance than the EN method of sticking a heated dummy into the bag. `I do think one of the ways they achieve such low weight and high warmth is by cutting the bags quite small, which would probably actually help if they ever did do EN13537 testing as there would be less air inside to be heated.
I am a little bit wary of the EN tests, and although I do get carried away comparing specs they don't always tell the full story. The Rab bags you mention (apart from costing around $1000 NZ) are from what I can tell not EN tested either.
"2012 saw the introduction of a revised version of EN13537 for sleeping bags. Rab have decided not to EN test their bags with fill weights of 800g and upwards. They feel that the revised EN test does not provide accurate results for bags operating at these lower temperatures. Instead Rab have provided a rating for these bags based on the EN 13537: 2002, the BS TOG results and real-life experience by their athletes and users - the value is know as the Rab Sleep Limit and this is the only value given for these bags." [from
http://www.downsleepingbag.co.uk/sleeping-bags/CHOOSING-A-BAG.html]
There is some interesting discussion of EN testing for cold weather bags on many forums such as:
http://www.trailspace.com/forums/gear-selection/topics/91375.htmlI kind of figure (hope) that most well made mummy bags with 800gm of 800loft down will probably have similar real world performance.
Another factor in this choice is that for the few specific trips I have in mind, I will not have to carry this on my back very far, so weight was not the first consideration (think basecamps, sleds, helicopters and porters in some locations).
Aidan, its great to hear from someone who has used these sleeping bags, thanks for the input!