In this paper, we consider the use of cooperative transmissions in multi-hop wireless networks to achieve virtual MISO (Multiple Input Single Output) links. Specifically, we investigate how the physical layer VMISO benefits translate into network level performance improvements. We show that the improvements are non-trivial (15% to 300% depending on the node density) but rely on two crucial algorithmic decisions: the number of co-operating transmitters for each link; and the cooperation strategy used by the transmitters. Finally, we present Proteus, an adaptive diversity routing protocol that includes algorithmic solutions to the above two decision problems and leverages VMISO links in multi-hop wireless network to achieve performance improvements. We evaluate Proteus using NS2 based simulations with an enhanced physical layer model that accurately captures the effect of VMISO transmissions.