Rapha, nice but a bit pricey?

The best designer jacket? Beats me.. haven't heard of this c_change stuff until now.

http://www.schoeller-textiles.com/en/technologies/c-change.html

Is it soft shell specific, or does it appear in shells like gore-tex / event? Is it an interior fabric or external?

It's the membrane so would be sandwiched between inner and outer. Mammut have put it in hardshells which are about £350