We're working out what we think - we'll add our view here!
Mountain Equipment says:
Superb all-weather insulation combining wamth, breathability and protection in a single versatile layer
POLARLOFT® Featherless insulation not only works wet or dry but, thanks to its blown construction, breathes effortlessly as well. Combined with our highly protective DRILITE® Loft outer the Superflux is a jacket that thrives as an outer or mid-layer in the most difficult mountain conditions.