My partner did it and it worked really well for them. They have CPTSD and noticed changes within a few weeks. IIRC, it helped reduce frequency and intensity of flashbacks and nightmares, and improved their ability to focus too.
They probably only did 8 total treatments or so and to this day it's one of the best treatments they've done. They were unable to drive at all for a few months (due to trauma) and were even afraid to be in the car when I was driving. after neurofeedback, they are able to get around in a car just fine.
I went to the first session and it seemed easy. You just watch a movie with electrodes on your head, and you have to calm your thoughts in order to block the bubbles on the screen and noise in the headphones. They were pretty exhausted after the first few sessions but after a few weeks, they were able to drive to and from the clinic themselves.
I hope to be able to try neurofeedback someday