I was curious enough to read the description, and as I went through it was mostly, "meh". Stuff I wouldn't mind for free, but not that I'd pay $250 for.
Then I got to this part:
Luna’s built-in smart alarm wakes you at the right moment of light sleep, so you can say goodbye to groggy mornings.
Luna’s sensing technology identifies the correct moment in your sleep cycle to wake you up at your highest energy level.
Now that seems genuinely useful. Something a FitBit could probably do for less, if I remembered to keep it charged and wear it. Which I probably wouldn't.
Still, this is an item that faces some serious durability issues. I think I'll let other folks test out the Gen1 version, and will consider a (hopefully cheaper) Gen2 when it's available.