I operate from an 800m grass strip, and often PA-28s and C172s land with either 2 stages, or no flap and takeoff with no flap selected. They then end up using almost all the 800m, leaving very little reserve in the event of problems.
I always take off with 2 stages and land with 3 (PA-28), and have never had problems with the reduced climb performance, even at MTOW. I never tend to use more than 5-600m for either takeoff or landing. I do not think this would be possible flapless.