Achieving synchronicity and tempo stability during a Network Music Performance (NMP) is not straightforward under heavy network latency conditions. Previous work on Global Metronomes has shown that it is possible to provide a universal time-reference signal to the connected nodes of an NMP. This paper illustrates the effects of using a global metronome and signal source-panning on a rhythmic performance. An experiment was conducted to evaluate the objective musical outcome and the subjective impressions of using these elements, applied to several pairs of Djembe percussion duets, under different tempo and latency conditions. The objective analysis in terms of tempo stability and synchrony, conducted from the perspective of an hypothetical audience, suggest that the use of a metronome achieves stability improvements at medium and higher latency levels, while the use of signal panning has been effective in improving the metronome efficiency. Subjective analysis data shows that the use of the metronome becomes challenging for higher delays while it was perceptually non-intrusive for the musicians for lower and medium delays.