So the grinder is my kitchen:

What a beautiful thing !!!
And it is all the difference. I am very impressed by the homogenous and fine coffee coming out of the grinder. And it is very quiet and fast. So back to my Rancilio Z11, incredible, the first shot of a double espresso took me 40 seconds or so instead of poor 10s before. Finally I can overextract the coffee and I feared it would never be possible with my setup.
Only drawback, as the machine has a dosing box I need to learn how to have the freshly ground coffee in the portafilter and not sitting in the machine and falling in the box after a lot of grinding and finally using the coffee ground 10 minutes ago... Yes I am not a bar finally...
I am happy