Dairy Don, most hyped place about shakes, but I guess people of mumbai dont know true taste of shakes. I tried rocher shake over there, but the taste was not upto the mark. The icecream sandwich was okish still not something for which I will ask people to visit. However talking about mumbai, bachelors is way too better, but limited outlets.
But if you really want to try some shakes, BIG CHILL is the place to visit, its in Delhi, but yes a must visit place.