Thanks so much for putting the link on BPL. Would have missed Will's report otherwise, and it is by far the best I've seen.
The SD Mobile Mummy 30 degree F. bag is about 50% (10 oz) heavier that my MontBell spiral down #3, so not sure if the arm holes and center zip are worth that much extra weight, but it is a nice concept.
The new Montane pull over rain shell looks to die for, but alas have acquired an M10, so will have to first see how that works out.
Miss Will's reviews on BPL.