Recently, the IEEE published the 802.11s standard amendment for wireless mesh networks using IEEE 802.11 hardware. Since most of the new techniques may be implemented in software, this allows to bring the benefits of mesh networking to a broad market of about one billion devices. The standard amendment describes new power save schemes which allow efficient energy saving for all mesh nodes. On the downside, the power save schemes will also degrade the network performance in terms of delay and throughput. In this paper we present a testbed analysis of the effects of 802.11s power save on mesh link performance. We analyze the effects on round-trip time and throughput in detail for different configurations and network parameters.