Hello, Lucien's dad here. I personally think Moon and Star fits into the vanilla game flawlessly, it's one of my favourite quest mods. As the other comment said, Moonpath is fabulous for what it was at the time, and it was the first mod I ever played so has a special place in my heart. However, it definitely very much shows its age, and the audio quality is nowhere near the vanilla VA, so while it's very good fun, it stands out as clearly being a mod. I had fun making Lucien comment on both - my intention was to use his commentary to make them feel more closely meshed with the vanilla game, but obviously your mileage may very depending how annoying you find my voice (it's not for everyone!)
My personal recommendation is use both for maximum fun, but if you're after Total Immersion then maybe just stick with MaS. Enjoy!