Hi @colorofblack
I think you don’t really need to use a subsurf modifier for such piece, I would rather use the bevel modifier on the edges that you creased, and also mark them as sharp.
Just make sure that you have auto smooth turned on too.
You can check this tutorial that covers that topic: https://cgcookie.com/tutorial/how-to-create-clean-booleans-with-blender
If you still want to use the subsurf modifier, make sure you use it after the bevel modifier and not the opposite.
Let me know if this helps!
Cheers,
/Thibaut.
