I have a Chillus Convolutus that looks just like that. I use it with a March 809 pump and 1/2" silicon tubing with PVC disconnects. Depending on temp it takes about 5-10 minutes per 5 gallons. Maybe 15 if the ground water is warmer or you're doing a lager. I don't have trouble getting it down to pitching temps though with typical Seattle temperatures. I have hit mid 50's without much trouble, and for ales I have to throttle the cold water considerably (maybe 3/4 the way.)
I sanitize it by recirculating the wort through when it's still near boiling (post whirlpool) and clean it by pumping boiling water through after it. It was worth the $75 CL purchase to me as it takes under 30-45 minutes typically to cool 20 gallons and is easier to clean than a plate chiller. A big step up from the garden hose CFC, and so far I've not noticed an increase in DMS from the process.
