Smart Watches/devices

[dataq1]

@PeaceLoveand Pizza;

Is there any reason to believe that the algorithms (used to evaluate detected signals) are identical between the two series?  
Probably no assurance.
It might be reasonable to assume that the algorithms are being improved with each new release.

But what I'm troubled by is that at some point the prior algorithms were valididated  with actual EEG signals.  At least we assume that validation to have been conducted.

[PeaceLoveAndPizza]

I do not know that there have been any major changes in the algorithm, but I do know the sensors have been upgraded.

[dataq1]

@Peaceand Love,
Same concern. Presumably the output was validated against actual EEG for both series. Which leads one to wonder, a) were a validations actually performed and  b) (considering the discrepency you describe) which series is providing the more accurate result.

* Assumes that you do not have two brains, each with it's own EEG signals !