Experimental validation and testing of solutions designed for heterogeneous environment is a challenging issue. Wrekavoc is a tool for performing such validation. It runs an unmodified applications on emulated multisite heterogeneous platforms. It downgrades the performance of the nodes (CPU and memory) and the interconnection network in a prescribed way. We report on new strategies to improve the accuracy of the network and memory models. Then, we present an experimental validation of the tool that compares executions of a variety of application code. The comparison is done between a real heterogeneous platform against the emulation of that platform with Wrekavoc. The measurements show that our approach allows for a close reproduction of the real measurements in the emulator.