As was mentioned, the key is to not use the boiling water that initially comes out of the chiller. I fill my HLT with some the hot water, to use for cleaning the brewkettle when it's empty. Within a few minutes, the water coming out of the chiller is cooler (you can at least touch it without burning yourself, even though it's still pretty warm) and that is the time to add the ice.
I tried using NO chilling water, and just using my HEX in my HERMS to chill a 5 gallon batch with ice. But it took 42 pounds of ice doing it that way- and so I never did that again. Combining the two- chilling to sub-130 with the chiller, and then using some ice and recirculating- would be a fairly efficient and cost effective way to do chilling.