I've had this monotron for over a year now and I still use it and it still functions perfectly.
Handling: It takes a while to get used to it, you really have to be a knob twidler so to say. But once you know the controls you can get the most amazing sounds out of it.
Features: I still discover new sounds from it, it is amazingly versatile. I use it in combination with a pedalboard which opens even more options.
Sound: The speaker inside the monotron is decent, not great but decent. It really shines when you plug some speakers in, it's like a new world opening.
Quality: I was a bit scared at first, it's all plastic but after using it for this long it really is quality made. Everything still functions great, not even some scratching when turning knobs, everything still goes smooth.
The monotron is great fun, especially if you're into weird synth sounds.