Over the summer I got my hands on a keggle. Clearly the immersion chiller and the keg were meant to be:
11 gallons of 212F down to 90F in 10mins. I assume the water temp from the hose was in the 30s.
Just started brewing and quickly discovered the importance of a quick cold break. My first 5 gal. batch was cooled in an ice bath, hour+ to pitching = meh. The second was with a rinky dink 3/8" <20ft immersion chiller that a friend graciously donated - not bad, but still took a good 15...