On your general-purpose lighting/non-kitchen area receptacle circuits, how often are you now installing 20A branches instead of 15A?

If 20A is installed, are you using T-slot 20A receptacles throughout, or sticking with 15A types? Come to think of it, just how common are domestic appliances with 120V 20A plugs? I don't recall ever seeing any during my time in America.

(Bathrooms notwithstanding as I know that requires its only 20A GFI branch now.)