widgeon: your correct, with the apical emergency floats you can land and take off as they have enough bouyancy to keep the tailrotor out of the water. ditching floats are approved for water landing only. operators must be careful to make sure they have emergency floats vs ditching floats, if they decide to alight from the water.
with regards to the extensions, have seen a number of operators keep the extension installed and just remove the bags when not flying over water.
one more advantage to apical floats on the astar is the mechanical pull system, no electrical system. apical also has the astar floats available with the liferaft built into the float bag, thereby freeing up cabin space.
dr