I've gotten consistently short estimates, a minute or two, that match Disk Utility's run-time since I've been running Snow Leopard; I believe Leopard also gave me short estimates and runs (although not as short as SL). I skipped Tiger and can't speak for it, but I remember Panther as the OS that took gave me absurd estimates and took absurdly long to run.
The new Great Equalizer is the SEND button.
In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire
