I agree too whimpy for a restoration. Would probably clean the tile - but that is not much of a challenge. FYI - we use them to remove the haze from tiles after we colorseal.
After we mop on our alk we than use our cimex to pre scrub the tile with grey or white pads not brushes unless it is a rough surface, it looks great to use in front of a customer and easy on the labour.
For the grout joints use a stand up grout brush and scrub by hand no machine will do a better job.
Mike that is a great idea hope they sell them hear.