Hi currently got 2 strix GTX 1080 in sli but probably going to return them due to an assured amount of coil whine. But in 2 minds to whether get replacmentz or get a refund and get a single Titan XP.
£1650 for dual gtx1080 water-cooled
£1250 for Titan XP
£400 cheaper I know I would lose some performance but not everything supports sli like when I had crossfire only about 4 games I played actually used the second card.