Borrowed one to do a travertine kitchen splashback that the customer didn't want the holes filling, tip them up further than 90degrees and you end up with grout running out of the back of em and down your arm. Also tried them using black grout on a big floor..spent more time unbloking the end of it than it would have taken to grout it normally...grout bags are great for doing small intricate bits like joining up 2 grout colours or going up against a stone fireplace or wall where you could end up staining the stonework