In multilayer IP over optical networks, the optical layer provides the lightpaths to transmit aggregated time-varying requests from the packet layer. By exploiting the traffic grooming, enabled by the cross-layer information exchange, the number of lightpaths to be established can be minimized by using spare capacity available on them grooming new requests. To this purpose, the transceivers that equip the optical nodes play a key role. In this paper, different transceiver models and technologies are benchmarked to evaluate their impact on the overall network performance. In particular, it is shown that deploying higher-performance transceivers provide major benefits to network operators.