In reply to crabduck: Agree about the build quality. It actually really came home to me when I started recently planning to do a multiday cycle tour. I'm planning to go as light as possible - and when I checked the weights of my older sleeping bags (two of which aren't nearly as warm as the Plasma) realised that they were all much heavier and bulkier. So then I thought, I can be 'tough', I don't need a super warm bag now it's spring - so I can maybe invest in something not as warm but light and compact. But on looking around the net at the usual suspects, unless you get into mountain marathon style bags, and quite big price tags, there aren't actually so many bags lighter than the Plasma 30, even ones that don't claim to be any warmer than, say, +5 or more! The 900 fill down is pretty special stuff allied to the amazingly light Pertex they make the bag from. But of course the price reflects that.
So I actually started wondering, could I afford a Plasma 30? But imaging my wife's reaction to this suggestion - decided no, and I would just have to find a slightly big dry sack and take the Plasma 15 on my first "bikepacking" attempt.