My husband and I used to use Holosync (Centerpointe) for 30 min-1 hour for 5+ days/week for nearly 4 years. He had done the Art of Living meditation before the biaural beats. I have tried to do traditional meditation for years pre-Paleo and had difficulty focusing. There were benefits to all of the above, but looking back we didn't feel it was the best return on investment (time and money).
We basically stopped Holosync after some Paleo biohackers/self quantifiers recommended Emwave for Desktop. It's uses biofeedback and is is nondenominational (doesn't matter if you are an atheist or a fundamentalist). Emwave is cheaper, and faster (about 5-12 min/day). You can track yourself very well. There are breathing exercises and games. You can install it on an unlimited # of computers. There is only 1 USB earpiece sensor (you pay for extra ones if you want). I tried the finger sensor but it didn't work very well, so I stopped using it. It's quite useful while traveling.
Over the years, I've found a disproportionate amount of meditation products and services (and gurus) to promote vegetarianism (rarer with veganism). The irony is that since our blood sugar is far more stable on an ancestral lifestyle (and cortisol less), I find that when I do sit in on a yoga or meditation session I don't get hungry (or think about food) the way we used to. That's a whole another hack, sorry for the rambling.
Anyways - Emwave measures heart rate variability and pulse, and is a good indicator of emotional state. There are different difficulty levels - low, medium, high, and highest.
I do not have any financial interests in any of these products. I tell people you should experiment and find what you feel most comfortable with.
