I think it is better, when the sonata-bc CSS class is not set on the body tag. It should be set on a div on the top level instead. This will ensure that only elements in the div will be affected by sonata admin CSS styles.
For example: I'm using the CKEditor in the Sonata admin panel, which has some overlay windows, Those elements are created as children of the body tag, so they're affected by the CSS styles of the sonata admin, which basically breaks all those overlays.
I think it is better, when the sonata-bc CSS class is not set on the body tag. It should be set on a div on the top level instead. This will ensure that only elements in the div will be affected by sonata admin CSS styles.
For example: I'm using the CKEditor in the Sonata admin panel, which has some overlay windows, Those elements are created as children of the body tag, so they're affected by the CSS styles of the sonata admin, which basically breaks all those overlays.
Currently:
Better:review #995