I love the bass and
I love the bass and the bluetooth connectivity worked really well too. My main concert though is the size of the vest. I'm a rather big guy (6'3", 130kg) and the vest is not comfortable to wear for me. As soon as I try to lean against my chair, the vest is pushed upwards and only covers a small part of my back (my girlfriend doesn't have that problem, but she is a lot smaller than me).
I understand that designing a new product of this kind is a challenge and you probably only have the tooling for a "one size for everyone" kind of vest right now. If you're adding some kind of XL variant to your lineup in the future, I'd buy it without hesitation. But with the current size it's more or less unusable for me, as I can only wear it without leaning against anything, which feels off and doesn't allow me to relax.