So I bought it with reservations, but it turned out to be the most useful "tool" for music lovers, it's the first thing I'll get for a job...
Especially if you have the tstak series, you attach it to your set and you're good to go.
Very good sound with super bass.
Very good durability and construction.
It's useful that it's also a battery charger, I don't have to carry an extra charger, I can charge my phone as well.
One negative thing is that sometimes when using Bluetooth from my phone, it disconnects and I have to reconnect it... maybe it's an issue with my phone, I don't know.