Well, I am a long term meditator, and an ex holosync user ( I like the product but not for the big bucks....)
I guess I have two thoughts to offer, that may or may not be useful for you.
First, watching my children grow up, I do not realy notice the small incremental changes day to day. But when I see my god-daughter or nephew every few weeks, I say WOW!
...Those small incremental changes add up when you are not noticing them!
The other thing is, as you might guess from my nickname, I like vitamins and health foods. (junk food too, a bit) I take my vitamins daily NOT to see an immediate efect, but for long term benefits. Like changing the oil in your car regularly, it wears down a little more slowly. Meditation is like that, reducing cortisol and the other effects of stress, slowly has a cummulative effect over time.
I still use my holosync from time to time, but also use my other recordings, do other forms of meditaion, qigong, etc. All part of good self care. I would probably still use the products if they did not want so much money for them, and if they werent so agressive int heir marketting push.