I have heard both and kept the New Primacy, the N40 is a tad brighter and has a little more sparkle in the treble, but with the New Primacy is has a special magic. The sound is very nicely balanced with great extension in both ends and plays every genre great. The thing is, the sound is seductively relaxing, you can listen to it for hours and hours and yet it is very very detailed, the bass is some of the nicest bass I have ever heard in a iem, it is nicely textured and plays it how it should sound, mids are a tad forward but with a relaxed nature and the treble is relaxed but nicely extened. Intrument seperation is very good and soundstage is bigger than most iems but not the largest I heard. The only thing you will need to worry is that it does like a good source and does detect hiss easily, so a good dac or dap is needed. Also it does scale very well with a nice amp, the soundstage opens up, instrument separation becomes much better and overall the sound becomes snappy and quick. Do give it to burn it, after 24 hours it starts to live. For the price of the new primacy, I say its seriously amazing bang for the back and competes high up there with the Sennheiser IE800, Westone W40 and Shure Se535 and many others. Best thing to do is try them out yourself.