Actually the Tyros did not do that well (The Technics KN7000 outsold it 2 to 1) however when the T2 came out it was a game changer, purely because of its SA voices, (Not up to pro standards of the time but for the domestic market WOW!) which really put the Tyros range on the map.
Bill
Yes i know...
Thats what i said, the least performing keyboard range of that time has grown to become the dominant force (atleast in numbers)