Hi, Kestas,
I have tried Cermax, Xado and RVS.
I tried Xado first, in several vehicles(powersteering, engine and transmission).
It did not work in any way.
Not any difference in power, fuelconsumption or noise reduction.
I tried Cermax in two engines.
It made the engines idle better(and quieter)and give a slightly better pulling force and improved MPG.
With RVS, I guess I was lucky, since it restored the diesel pump and reduced fuelconsumption 14%.
I haven't tried Cermet, but I have heard that it should be good.
Since I also have available several user testimonials from Sweden and Denmark, I also contacted some of them, before I ordered RVS.
Testing have shown that RVS is capable of making up to 1.1 mm of metal ceramic on the most worn places.
It reacts with heat.
RVS is the best I have tried personally, so far.