Hello, I just wanted to share my experience with the muse meditation headband. I'm amazed by it. I don't know if it's just my beginning excitement or if it's improving my meditation tenfold on it's own.
I was told this device was best for beginners, but I believe it's best for medium level meditators (like myself).

I reach concentration levels that normally need luck and a good day to achieve. Also during these high concentration levels thanks to the birdsounds that occur, I become aware of the collapse of the inside-world, and when I am in access-concentration with one pointedness of the mind.

I believe that those states of concentration are like 2 hours of relaxed meditation condensed into 2 minutes (metaphorically trying to quantify it). The thing is: in between the breaths, the focus is resting on that empty spacious awareness with FULL concentration. It's like the space/awareness Adyashanti and Rupert spira are talking about becomes 10x more intense and noticeable.

It has downsides (in the beginning at least). The biofeedback (birdnoises) make me realise that I am successfully meditating, and then I start thinking about me meditating good. And the intense concentration is very hard to keep up for more than 5-10 minutes.

But the important part is: You actually know when you are successfully meditating, what happens when you fall into deep concentration so you can reproduce that later on.

I had the device for 3 days now, so that's just my initial commentary on it, I'll do another post in a month.

Does have biofeedback devices they find useful? What are tips to make the most out of those devices. Any other pros and cons about it?

I hope I'll be able to maintain access concentration for longer periods of time.