I couldn't agree with you more on the Cocteau Twins...they are really bionic! I saw them live and they had a really intresting blend of computer-controlled rhythms and sheer human emotion... I met Elizibeth Frasier! she's sooo cute! I was standing outside Roseland NYC after the show and the whole band came out! I shook her hand.
Anyway I also think Dead Can Dance and Portishead are really extropic, They are both uploading folk music, if you can understand that...storing ancient aesthetic knowledge. Deep Forest is another extropic group. I think that using computers and synthesizers to store, manipulate and perform ancient musics is a really extropic endeavor.
Anyway just thought i'd add my two cents...