It is true that it is difficult to know the differences. According to my research (referring to the instructions for my machine) the SteaMitt 11 in 1 also has a steam booster on the floor cleaning head and a keyhole at the back of the handle for hanging the machine (on a screw head or hook).In addition, the SteaMitt 11 in 1 has a steam booster on the floor cleaning head and a keyhole on the back of the handle for hanging the appliance (on a screw head or a hook) when stored. In addition, the brushes are different: the joint brush of the SteaMitt 11 in 1 seems to me to be wider (5 rows of bristles). On the other hand, the SteaMitt 11 in 1 comes with two other long brushes: one with nine rows of bristles (also synthetic) and one with five rows of wire bristles. However, the SteaMitt 11 in 1 is delivered without a round brush (a set of round brushes can be purchased as an accessory). Despite careful reading of the user's manual, it is difficult for me to tell you exactly what the differences are between the two devices: I hope that a user of the SteaMitt FSMH1351SM will be able to complete my description to remove any uncertainty or inaccuracies. Personally, I am very satisfied with this purchase: this steam cleaner makes my work much easier and the results are very convincing. However, I only use it very occasionally for parquet floors, as I prefer the care (and fragrance) of black soap; similarly, I clean my tiled floor with black soap from time to time to nourish it and restore its satin shine if necessary. When I bought the product I followed the advice of "Ombre" (see question n°1).