The problem with all of these companies is that they completely miss the way you shop for a helmet.

Step 1: Find a helmet that fits well and fits comfortably.
Step 2: Pick a version of that helmet that has the features you want.
Step3: Buy it.
Alternate Step 3: If it doesn’t have the features you want, buy it anyway.

Features like this, no matter how good they are, will never - CAN never - be more important than fit. Tying the technology to a particular helmet design sinks it before it even starts. Make it a universal, bolt on style accessory or don’t bother making it.