I'm fairly sure object() also returns an object which is unique and distinct from all other objects. The only difference as far as I can see is that make_sentinel returns an object that has a unique and distinct type from all other objects, but I don't see why you'd be checking the type of your sentinels in Python.

Hehe, boltons.typeutils.make_sentinel should really be documented better for more experienced developers. A few small advantages: a nice repr, pickleability, and (back to the first advantage really) good rendering in a Sphinx autodoc context. :)