It takes about as long to stuff around and get the chiller done, unless someone is super organised like the people that hang their ic in the boil for sterilising and basically ready to chill at flameout, most I've seen though would spend 15-30 minutes getting it into a fermenter. Especially with plate chillers.
So, in comparison I think this method actually brings the wort below the hop isomerisation temp a lot quicker. I think Florian used a corny to NC and dunked that in the pool so he might be able to tell if that chills even quicker.
I saw a video ages ago of someone in canada brewing that basically take the kettle outside and sit it in the snow. Job done.
Up north there isn't cold water but there IS a LOT of it so adapt. I used to live upstairs and this was straight off my balcony (note the rope) so easy.