Which step response matches the system transfer function
The final value of the step response is the DC gain of the closed-loop transfer function, which is generally different from the open-loop DC gain.
Assuming unity gain feedback, the feed-forward transfer function $G(s)$ equals the open-loop transfer function, and the closed-loop transfer function is given by
$$C(s)=\frac{G(s)}{1+G(s)}\tag{1}$$
The final value of the closed-loop step response equals $C(0)$. With the given value of $G(0)$, which I would interpret as $-3$dB, the final value of the closed-loop step response should be around $\sqrt{2}-1\approx 0.4$. The step response in Figure $1$ seems like a good match.