I picked up La Decouverte ou L'Ignorance in the late seventies (in Edmonton, Alberta no less) and it quickly became one of my favourites - it is still fresh and I have a CD copy. I subsequently purchased some of their other recordings when visiting Lyon - one was terrible - different sort of format but the others were good.
Haven't heard their recent stuff though a quick google search yilded this web site - they still exist, I believe.
http://www.bretagnenet.com/tri-yann/
La Decouverte ou L'Ignorance will always be one of my all time favourites
Rana