We formally establish that IEEE 802.11 yields exceptionally good performance in the context of wireless multi-hop networks. A common misconception is that existing acceptable CSMA-CA random access schemes like IEEE 802.11 yield unfair and inefficient rates in wireless multi-hop networks. This misconception is based on works which study IEEE 802.11-scheduled multi-hop networks with TCP or in saturation conditions both of which grossly underutilize the available capacity that IEEE 802.11 provides, or use topologies which cannot occur in practice due to physical layer limitations. To formally establish our thesis, we will derive worst case performance bounds on IEEE 802.11 in multi-hop networks. We first characterize the capacity region for any IEEE 802.11-scheduled multi-hop network. We then use this characterization to compare the max-min rate allocation achieved by IEEE 802.11 and optimal, and find that: (i) IEEE 802.11 is never worse than 16% of the optimal when ignoring physical layer constraints, (ii) in any realistic topology with geometric constraints due to the physical layer, IEEE 802.11 is never worse than 30% of the optimal, and (iii) in typical topologies IEEE 802.11 attains more than 55% of the optimal throughput. Considering that the state-of-the-art distributed approximations to optimal scheduling achieve lower worst case bounds than the above,IEEE 802.11 is surprisingly efficient. To ensure that this good performance is achievable with a distributed rate controller, we design and implement two rate control schemes, WCP and WCP-CAP which achieve close to optimal performance.