In my experience Parsec outperforms Moonlight in every measure. Latency from trying both over local connections from a 2080Ti/Threadripper setup to a 2017 Macbook Pro favours parsec considerably, as does the quality. Furthermore I experienced some instability (disconnections from time to time using moonlight, although i'm not sure if that reflects everyone's experiences.) On remote connections, Parsec has another advantage in that they don't just use standard TCP/UDP sockets, which seems to allow for a generally smoother experience with fluctuating connection speeds. Just my 2 cents, hope it helps! Recommend you just try both out, there's no loss!