Here are some day one impressions of the Vega, probably did six hours of listening with them today. Sources were a Pono player, a GOV2+ (through an iPhone 7 and a Macbook Air at different points), and a Schiit Jotunheim with Modi Multibit.
The TL;DR is that these are the paternal twins of the Andromedas. Both are equally excellent but have different strengths. The Andromedas have an amazing tonal balance, wonderful soundstage and airiness, and practically sound like speakers in a room instead of monitors in your ear. The Vegas have seemingly limitless, powerful bass that commands your presence but doesn't detract from or bleed into the mids. They have a more natural sounding decay and exceptional timbre and texture. They're both insanely listenable, and in terms of technicalities I would say they are even. So the only question is which FR and presentation will you prefer.
Personally I find these hypnotic. With the Andromedas I felt like I always had to listen to just one...more...song. With the Vegas I'm wondering why I would ever take them off. They really draw you into the music, a symptom of both their exceptional texture/timbre but also from the palpable bass that you can feel. I don't know how a tiny IEM is producing better, more plentiful, and more extended bass than most full size cans, but it's simply wonderful.
I think people are going to end up on either Team Andromeda or Team Vega (except for those with resources to own both!). They're very different IEMs that are both the best at what they do. I waffled on getting an Andromeda for a long time and with the Vega I decided to bite the bullet and I'm very glad I did. That being said, if you're a big fan of the Andromeda, give these a listen before you buy, because you may not like the qualities of the Vega and how it differs from the Andros.
If you love powerful, deep, well controlled bass, you must hear these.