Their latest issue at least. Early on they spent actual time engineering a better tracking solution, then got stuck for a while trying to get their design to pass FCC cert. Now, they have a working product that passed FCC cert, and are trying to figure out how to produce it reasonably. Their early design would have actually cost $5000 a unit to produce. They're actually a-ok with kickstarter backers asking for refunds, because they're going to be losing about $700 per kickstarter order.
Their last update was lengthy and included their short term and long term goals. They've secured funding to produce the kickstarter kits, and have miniaturized it with an emphasis on mobile to bring cost down. Compare this prettied up render of the kickstarter edition (the actual 3D printed protos are even larger:
to their new kit:
They claim they are finally actually manufacturing them, at an actual plant, and will post updates through the manufacturing process, and will ship in october (knock on wood). I have no delusions that they will corner the market, I just want mine because it can act like additional SteamVR controllers and that's actually really useful for quite a number of things. Example - I can pretty easily write a program that could use 8 trackers (Vive Headset, 2 Vive controllers, plus 5 STEM trackers) to do some rudimentary mocap for skeletal animations, or using one stem tracker for an Mixed reality broadcast, or even using the STEM system as a way to do bootleg 2-player Vive development.
In other words, I still see a lot of utility in their product as a developer, and thus I still want mine.