It could be my lack of proper understanding of NFB but the Muse is basically forehead only sensors. Add one you have a bit more to work with, but I think the Versus has come closest to what I was looking for in terms of headset and coverage but it has no API and they are the only ones who make protocols for it. They also charge a monthly fee instead of selling it for a single price.
At the end of the day I keep hearing conflicting things about NFB, what works, what doesn't, and I am concluding that I don't know enough to judge this anymore. But I've met those who claim that only a full head EEG is what one needs to move the needle.
Originally I was looking for a system that can give me a visual overview of my state of brainwaves, with maybe some guidance to what does what I am seeing translate to. I wanted to get familiar with my states of mind in a way other than by subjective internal experience. But I don't buy that a few electrodes on my forehead can give me a comprehensive picture. However I know that more head coverage might give me too much info and without some analysis it won't be useful to me.
I thought OpenBCI would be what I am looking for but it is not user friendly, and cumbersome to set up (with an expensive head mount if you want to go that route).
Again, if the Versus or something like it was made available to folks to create protocols and apps for, that would probably be what I am looking for. More head coverage, dry electrodes, wireless bluetooth.