The quality strongly depends on the settings (dozens of parameters can be configured) linked to the shape of the object, the settings in Repetier are very extensive, for example we can adjust the filling "patern" (by default, a massive part is filled with a honeycomb to save weight and material), the printing speed can be boosted up to x3, the material flow up to x1.5 ...
See the evolution in 3 days:
1) The cooling cone, everything 1er object ... result rather mediocre!

The base is about 40x40 mm to get an idea of the grain size.
2) The housing of the electronic plate:
During the printing of this piece, I played on the speed and the T ° of extrusion, one sees it in some layers better finished than others:

3) My 1st "trinket"


4) A hand, complex shape and my biggest object at the moment:
5) The 3 objects side by side:

This is what I could do as evolution since Monday afternoon ...
I think the quality can improve even if a mechanical surface treatment (polishing) or a paint / varnish can make the finish impeccable ...
To be continued!