IMHO, the, "Slimline", was marginal when new. The suction was okay but I would have used it as a garage vacuum and to clean my attic. If you had wall-to-wall which was prevalent at the time, you would never get your carpet clean.
It would have been a nice above the floor cleaner if you had a quality upright. Kind of like how Oreck sold those plastic cannisters with their uprights.
Keep in mind, I started this with, "IMHO", so don't go nuts.