Tarok,
I have the larger of the two Werther compressors, the one that produces 4 bar/55 psi; on the back it is called the Werther Three. The reason I wanted this one and not the lesser model is my son and I can plausibly think of wanting to paint at the same time, and I wanted to be able to do that.
It was louder than I thought it would be, but acceptable as compared to my other industrial compressor. I'm still getting used to it, but am enjoying being able to paint whenever I want and not have to fear waking up the whole neighborhood.
I find I am having to adjust my paint mixture alittle to the thinner, because I am used to having so much more l/m behind my airbrush. By this I'm not saying I have to adjust the levels tremedously, it was bothering me just enough to change what I have been using before.
The only thing I really have against the compressor is the noise level - and that is most likely my own subjective desire that was let down, not any actual factor. After putting the compressor on a anti-vibration matting it is very nice.
Don't know if that helps, but anyway best of luck!!