This mini keyboard keys is one of the many variants of mono synth described here:
http://weltenschule.de/TableHooters/Fujitone_1.html

- For how long have you been using it?
6months
- What thing do you like most/least about it?
Pure square wave. Good gameplay, because the synth responds very quickly to the game
There are only two variants of the basic sound, with varying degrees of release.
- Did you try many other models before getting this one?
I have 4 or 5 mini keyboards similar (Hing Hon EK-001 for example)
- What is your opinion about the value for the price?
A 1 € at the flea market is uen good basis for the circuit bending! I intend to adapt the keyboard controller for a WSG ( http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/WSG_Reborn/WEIRDSOUNDGENERATORREBORN.php?page=WSG ) dressed in white!
- Knowing what you know now, would you make the same choice? ...
Sure.