I bought this for the delay effect, which it does decently for it's cheap price.
It also has an triangle/square wave oscillator, but the ribbon controller is very sensitive and not quantized so it's difficult to play melodies. Good for effects though.
Filter is crunchy with just cutoff and no resonance.
Delay sound quality is unique in it's dirtyness, lots of digital noise, and feedback and time parameters which is kind of pain sometimes to get right.
Only big con even for the price is somewhat short battery life, but that depends on usage of course.