Why bother? Just learn the traditional notation.
The triangle/sharp on a leger line is hard to read.
What about courtesy accidentals?
And what do you do when you want to write in an extra reminder to yourself? The giant flat/sharp/natural sign so you can't possibly miss that note again.
The videos on the main page aren't that helpful. It's people sight-reading. They could be reading a lead sheet. I can't tell.
Play what you see... Traditional notation does that. Although with anything you don't actually play what you see. You play what you think it should sound like, what the composer meant (what you think they meant), or how you interpret the notation, etc.
Nothing is lost... So it's like traditional. Ok. That might make it more work to sketch something out. You can't just jot out dashes for the note heads. You'd have to be careful to make a triangle or diamond.
Easy to learn... assist memorization... So does traditional. And there are tons of teaching materials out there.
It does look simpler on this page though.
https://www.simplifiedmusicnotation.org/plugin.phpPhotocopying it would smudge the noteheads a bit. Those diamond/flats... They're going to start looking like regular noteheads when it gets smudged.
Someone would still have to learn to sight-read with this. It's still going to take some effort to read a piece. Just because it's new doesn't mean it's going to solve anything.
A disadvantage.... I can mentally 'feel' the key by all the sharps or flats in the music or key signature. This notation doesn't have that. It's all the same look.
I'm not recognizing names with the endorsements. Sounds bad, but starting off with a percussionist... Made me wonder. And community college teachers/performers? That's not really impressive.
Website's not that impressive.
There's probably not much if any music available.
Might be a fad. It's copyrighted for 2008 though. It looks like a site selling a few method books and a few plugins for Sibelius maybe.
Otherwise, it looks like another example of someone trying to improve music notation. I don't see it sticking though.