No chill substantially changes the beer. The continued heat affects the alpha acids from late hopping, destroying the lighter elements and causing isomerisation and therefore extra bitterness. It may work for some styles but if you want a late hopped flavour you need to rely on dry hopping. My beers are vastly better using an immersion chiller because I like my late hopping.
Bugger. I knew there had to be some catch to this excellent time and water saving idea. I like my hoppy beers... :-(