Hi Pilou,

re:
> Boolean Operation takes some times! A Boolean Diff with a Simple Sphere takes 20 sec! ;)
> Does it the same for you ?

This is probably because of the relatively high face count in the model. Your model appears to be made up of all triangles instead of being a quad-dominant mesh set up for sub-d smoothing. So because of that you're getting a lot of little tiny faces.

The sub-d importer is primarily focused on converting sub-d models, not non-sub-d triangle mesh models like you are using there.

- Michael