Installed in a Suzuki Vitara on the factory head unit with hi input and drives a pair of Alpine S2-S65C speakers in the front doors and a pair of S2-S65 speakers in the rear. The RCA output was connected to the active Macrom sub, the SW-250A. Compared to the factory audio system, there’s no comparison—it’s 1000% better.

+Positives:
Small size, it fit in the second floor of the trunk, as if it’s not even there
Class FD, doesn’t heat up, doesn’t require much power
4x100W RMS @ 4Ohm on each output
Automatic Hi input detection is very convenient if you don’t want to change the factory head unit
It has low THD, but since I use it with hi input, unfortunately I can’t enjoy it.

-Negatives:
The most important negative is the fact that the speaker output terminals are facing downwards, which makes installation difficult.
Personally, at this price (289€) I would expect it to have a built-in DSP like some HELIX models.

Very powerful, perfect sound

Simply perfect, the sound took off with the gmd1004 on the dashboard. Then with the gmd8704 I have no words, you just sit and enjoy the sound

The most important thing is that it is discreet, it fits into the car's dashboard, so you don't have the mess in the trunk with cables, etc. It provides that little extra sound that you need... everything is good then

But this little gadget rocks. You can hide it wherever you want and it produces a clean, high-quality bass sound!!!

A satisfactory power amplifier with a small size that can fit in the dashboard. Combined with front speaker replacement, the result is spectacular.
Drawback - perhaps - the fixed gain, you cannot customize it.
Pay attention to the power supply connection to avoid "clicks" from the speakers when the engine is off.