Before getting the bluebox, if I wanted to record a jam or similar, I needed to plug all the synths into my line mixer, fire up the daw, set up a session, etc etc.
With this, I literally wake it up and hit record. Brilliant box, massive timesaver and means I can record whatever I'm doing whenever I want.
Sound quality is good, haven't had any noise issues. The supplied microSD card needs replacing, and the new firmware allows you to use it as an interface, which is insane for the price. It takes up very little room too, which was a huge bonus.
Be warned about the cable size though - the cheap cordial cables I bought needed cutting down in order to get them to fit properly!