I have an advantage in that I brew with a friend all the time so our system works with four hands. I'm not sure it would be efficient for solo brewers.
We are doing full boils and cool by placing the boil pot in my sink. 2 bags of ice are poured around the outside of the pot. We add lots of ice cream salt and then fill the sink with water to just below overflow. We add two gallon sized ziploc bags that have pre boiled frozen water inside. You have to pay close attention to the bags because many have pin hole leaks.
One gently stirs the ice bags in a circle avoiding aeration. The other guy spins the pot (which becomes slightly bouyant) and stirs the ice bath. When the temp of the wort is under 90F, we lift the wort and drain the sink halfway. Add one more bags of ice and refill the water. We stir the wort more vigorously and you can watch the break form immediately as the temp drops to 68F within 1 minute. Total time averages 9 minutes from boiling wort to 68F.
Afterwards, we remove the ice bags and clean the outside in sanitizer and back in the freezer. We usually get three or four rounds before the bags get beat up or popped open.
Down side risk is if the ziploc opens .... Otherwise, it seems to work great. How fast does an IC or CFC cool?
