A dirt sensor tells you when that particular machine is no longer finding dirt. It does not necessarily mean carpet is clean.
I personally am not a fan of the Kenmore Intuition. The suction unit has a lot of power and hose handle are intuitive for easy operation. However there are major durability issues with the power nozzle and wand system. Tiny wheels on bare floor brush breaking off, scratching floors, broken connection back into power head. Additionally power head lifts off floor when handle is about 12" from the floor. Maneuverability and overall cleaning power with that power nozzle is very unimpressive to me in comparison to the bottom line Kenmores or Progressives. The Lime green, Tangerine, Blueberry and White are all the same power nozzle and suction power is virtually the same across the entire Kenmore canister line. The only thing you are comparing is features.
The Simplicity Gusto is a great machine. Very quiet, powerful, great cleaner. However I've heard rumors that Tacony is redesigning its canisters and they may be debuting a new model later this year. Therefore depending on your urgency with getting a machine, it may behoove you to wait and see what Tacony comes out with later this year. As we are now in the second half of 2013, the wait isn't too much longer.