1. A non-transitory computer readable storage medium storing instructions for causing one or more processors to perform a method for assessing performance of a computer resource service, the method comprising: sending, via a network to a system monitoring performance of the computer resource service, a request for performance metrics of particular configurations of computer systems from among a plurality of configurations of computer systems of the computer resource service, wherein the system monitoring performance uses test virtual machines on different ones of the computer systems to collect performance metrics for the plurality of configurations, wherein the request specifies filters that comprises one or more parameters that identify the particular configurations of computer systems; receiving, via the network from the system monitoring performance, a response that includes a set of the performance metrics specified by the one or more filters in the request, wherein the set of performance metrics comprises performance metrics for different ones of the configurations of the computer systems; selecting, based at least in part on the set of performance metrics received, a configuration from among the configurations of the computer systems of the computer resource service; and sending a request to initiate a new virtual machine in the computer resource service according to the selected configuration.