Before revision:  We show that if estimation is performed by an ideal observer of the entire trajectory of receptor states, then no energy consuming non-equilibrium receptor that can be divided into two pools of bound signaling and unbound non-signaling states can outperform a simple equilibrium two-state receptor.
After revision:  We show that if estimation is performed by an ideal observer of the entire trajectory of receptor states, then no energy consuming non-equilibrium receptor that can be divided into signaling and non-signaling states can outperform a simple equilibrium two-state receptor.