As promised in this post before my trip, I'm going to give an 'initial findings' review on the Cumulus Quantum 350.
My experience of down sleeping bags prior to this is non-existent so please bear this in mind whilst reading.
This was the first time I'd used it on a trip and just bringing it was proving useful - without even getting it out of its stuff sack! It packed so much easier than my last bag and my 49L Golite pack had so much more space as a result. The biggest benefit for me was the weight at 680g inclusive of the stuff sack.
The conditions/temperatures on the two nights spent using this bag were quite different, so was a good initial test.
The bag lofts really easily and a few shakes is all it needs to set it off. On the first trial on Yewbarrow (627m) it performed as I expected. The night was damp, very windy and temperature hovering around 3°C. I (as always) went to bed in my base layer and found it perfect. At around 6am I woke up feeling a cold draft on my upper body and realised I must have opened the cord around the neck baffle during the night. I closed this up and was immediately warm again.
The second night was spent at the Wasdale Head campsite in the valley where the temperatures were noticeably warmer than the previous night. Here I slept with the same base layer on and at one point in the night had to undo the draw cord to let some air in. I slept the remainder of the night like this and woke to be toasty once again!
We had very wet conditions throughout the weekend and inevitably there was an occasion when water fell in onto the bag from the baffle on the tent door. The Pertex Quantum fabric is featured throughout and as advertised beads water very well. Its also ludicrously soft against the skin which just adds to its appeal and makes you want to climb inside straight away!
I'm 5' 7" and found the bag is the perfect length for me. I'm not sure that anyone approaching 6' would fit inside quite as easily. The width of the bag is good too and I never felt it was too narrow or restrictive and it was just right to keep out any unwanted dead space inside the bag.
If I had to criticise the bag in any way based on this limited use I would pick on the hood, which I think could be just a little deeper. When you pull in the hood using the draw cord it tends to sit on the top of my head whereas I prefer my hoods to come forward over the face slightly. I suspect this is a very personal gripe and the majority of people will probably (and correctly) just think I'm an idiot!
I have to bear in mind this is my first down bag so I don't have any other experience to draw any real comparisons at this stage, but as an initial test I was suitably impressed with it. Paul, who has bought the same bag, was just as impressed as I was. He did notice that my bag seemed slightly more difficult to stuff into its sack than his and also didn't go down as small. We both found this really hard to work out but we'll weigh them both at a later date to determine if there is any measurable differences and report back.
I'll post another review once I've used the bag some more throughout the winter months