thanks..
as it's a firts batch S2..
i change the firmware (thanks to Lawsy)
the Z screw (free .. thanks to solidoodle),
i add the anti-wobble-nut preloader(with a big O-ring instead of a Spring, thanks to matt_johnson)
a glass bed with kapton (i don't like the hairspray)
i do a simple leveling bed procedure and a extruder calibration (thanks to Ian Johnson )
and a lot of time... (tie interceptor at 0.1mm anyone ? between 11 and 12 hours... i love to print when i sleep)..
but the S2 can do a lot of pretty good print just out of the box..
now i like to print between 0.18mm and 0.3mm... 0.1mm it's just too much time for not a big win ( i love 0.2mm with acetone bath) ... and 0.3mm is good for a lot of thing without a lot of little details..