These don't offer enough to make it worth buying over a cheaper regular MagicBand (or just reusing an old one if it still works).
I couldn't care less about lighting up with fireworks etc. -- I wouldn't be looking at my wrist during those shows anyways -- and the other functionality is too limited right now. The bounty hunter game is the main selling point but it doesn't look anywhere near as interesting as the wands at Universal or the old Sorcerers game.
I imagine they'll eventually add more to make it worth it, but who knows... it's not like they ever really did much with MyMagic+. It also seems like they could let you do all of this via your phone if they wanted, and that may eventually happen.