The main shortcoming: the total lack of volume control, either as input, output. ...
Another negative: wiring must be changed depending on the allocation method chosen effects (4 possibilities) = 4 separate connection 4x mono, 4 stereo effects in series = effects; 2 + 2 = 2x stereo ...
For each type of effect (reverb, delay, flanger, chorus, phaser, rotary) there are about eight different modes: (ambient, live, gated, dynamic ...) with common parameters and one which varies from mode to another (hence the need to consult the manual often enough to remember the function of this parameter in this particular way of this type of effect).
all effects are dynamic mode, which allows you to vary the intensity of an effect, or a parameter depending on the volume of the sound source input.
overall editing is easy, despite the absence of the screen, the parameters being screen printed on the front (except the famous that changes depending on the selected effect in each mode type parameter)
His late 90's standard digital sound for effects such as chorus, phaser, flanger we prefer the analog reverbs sound too metallic, the delays have some nice options.
I would not pay more than 75 € for this device. Despite numerous opportunities for routing, the many possible combinations of effects: it gathers dust. The sound quality is very reasonable; he begins to date but it can still serve today.