Sound quality
Like I mention in this video, the flare jet 2 is very similar in terms of sound to the jet 1. I go into more depths about this and how my listening experience confirms this. Whatever I wrote for the jet 1 almost always refers to the jet 2 as well. Bass is absolutely the best quality for this in ear monitor.
Build Quality
Build quality differs from the jet 1. The jet 2 is made of aluminum and contains more "quality" parts.
I talk about this in the video as well but to summarize, it is basically the same thing but made in aluminum,
please refer the the video for more in-detail descriptions and usages.