I have one also, along with a quilt halo. if I am doing FMQ on my domestic machine then I do use the slider, but the slider is small, so it is only good for working in an area that size, the rest of the quilt will still have friction across the rest of your table, so you need to take that into consideration if you are doing a quilt on your DSM. I haven't used it in years, as I have a gammill long arm and do all my FMQ on it.
as for the quilt halo - it helps too.