Is there an advantage in using atlases for 2D animations instead of sprite sheets?

I've never seen a formal definition of 'sprite sheet'. In my $$anonymous$$d a sprite sheet is regularly divided where an atlas need not be. So all sprite sheets are atlases, but not all atlases are sprite sheets.

Assu$$anonymous$$g you have more than one object that uses a particular sprite sheet, you want to avoid any animation solutions that modifies the material properties such as $$anonymous$$aterial.mainTextureOffset and $$anonymous$$aterial.mainTextureScale. You want one that modifies the uvs in the mesh. NGUI modifies the uvs.