Fractionally disengious this (although nothing by marketing standards ). No doubt nice bags these but they've not improved the down they're using
The old stuff mostly all used that 750 EU/850 US stuff that only the expedition bags seem to now use. So (slightly) worse down by and large.
It does seem like the construction must have improved slightly as the ratings seem very similar to their old (very good!) quantums, even with the slight down downgrade. So an impressive piece of engineering to compensate.
(its not like the quantums were designed badly after all ).
I suspect that 850 being the highest fill power refers to down they can get enough of to produce in sensible quantities. Both Yeti and PHD are small manufacturers who are only using 900 FP EU stuff in a fairly small portion of their ranges.
A couple of intriguing things which their (not always entirely helpful) website doesn't clarify:
a) Webtogs seem to suggest that at least some of these bags have been EN tested, with the quoted comfort figures corresponding to the comfort limit (the middle figure.). Commendable that they did this but odd they don't seem to mention it on their website
(especially as they look to stack up rather well in comparison!)
b) Are they still doing different lengths? No obvious signs of it.
Fractionally disengious this (although nothing by marketing standards ). No doubt nice bags these but they've not improved the down they're using The old stuff mostly all used that 750 EU/850 US stuff that only the expedition bags seem to now use. So (slightly) worse down by and large.
I have been looking at these bags and trying to puzzle them out for a week or so now on the RAB website. The lower spec down for some of the bags and the quoting of US fill power was the first thing I noticed. I was thinking of buying a Quantum Endurance 250, but there doesn't seem to be an alternative bag with comparable spec in the new range. The new range seems a bit overly complicated. It seems a bit misguided to add bags aimed towards ultra-lighters and in the same gesture reduce the quality of down i.e. the weight to warmth ratio in all but their expedition/high altitude type bags. And the new so called light weight options seem over designed.
Yes, the ultra light section of the range does seem to be suffering a little from the fixed weight. Full zip on the top bag and microlight shell on the liner bad do seem like odd decisions really.
Still the design, and UK filling, is clearly making the down do good things. Its an admirable achievement really, even if the fill downgrade makes it seem rather phyrric!
Comparing to ME's Zeros (both ranges seemingly - but not confirmed in RABs case - EN rated and very similar fill powers): Neutrino 200 = 705g/2 degrees, 400 = 920/-4, 600= 1125/-12.
The alpines at 745/0, 970/-6 and 1185/-14 - and water resistant - do seem simply better than the Neutrino's which could maybe have done with a half zip to save weight.
PHD of course are a bit like the Zero's in terms of minimalism but better down and even less features (esp zips). So a minim - with 400g of down! - and dri shell weighs about the same as a Neutrino/Alpine 200 (and will be a lot warmer.).
The Rab sleeping bag designer is, I think, ex Macpac... as far as the down goes, I'd be very surprised if there wasn't an ulra-lightweight bag with the top spec stuff in quite soon. Don't ask how I know etc. There's also lighter weight fabric somewhere down the line, which should lose grammes too.
Actually the other thing which occured to me recently about the weights in these bags is their length. Ok so they're not offering length options anymore, one assumes for cost reasons. Well fine properly tall people have other options
What is notable however is that they've felt oblidged to keep the base length very long - nearly 6"3' person height for the male ones.
Now if you're around 6" or so thats OK, but if you're more a bit under its actually a non trivial extra amount of weight to be carrying around.
ME for comparison do 180cm/200cm user lengths (standard/long bag.). WM are 5"6'/6"/6"6' and I think PHD are very similar.
you are aware that us and eu fill power are not the same. the us fill rating for say 800 requires more down than its european equivelant. so in fact you get more bang for ya buck. apparently they changed it so they could sell them in america and keep them happy over there.
straight from rab's mouth.
Yes I knew that. The EU vs US fill powers is fractionally sad as they used to be very (unusually!) good this way - giving both figures for all their down. Now they're a bit mixed up, and not making it clear they're using US figures on their website/publicity etc. You can understand why, but still.
The second part seems deeply confused! Lower fill power down == more down for the same warmth == (holding design etc constant) a heavier bag for the same warmth == not a good thing.
Not a fatal thing either, but try to claim that its a benefit to use lower quality down is pretty silly Its not critical either of course - 50g - 150g extra perhaps depending on overall weight of bag?
The EN ratings are nice of course, as give a good basis for comparisons.
). No doubt nice bags these but they've not improved the down they're using 
