Humm .... what you use depends on the texture you want.
If you want a coarser texture you would want something like the "S" shaped wire masher, or a German potato masher
, or even a blade type pastry blender
(the wire type pastry blender
would depend on the stiffness and strength of the wire - some are so flimsy you can't even blend pastry with them). If you really like some lumps - you could use a french fry cutter
For a finer texture you can use a potato ricer, or press the taters through a coarse sieve, or use a food mill with the coarse plate. You could also use a box grater, or a food processor with the grating plates.
"Plate base" mashers with round
, square or diamond openings, like the Oxo at C&B, can give you an "in between" texture depending on how you use them.
Of course, what you get using an electric mixer depends on speed and time - anywhere from coarse smashed to creamy whipped.
That OXO masher looks good - certainly easier to use with that horizontal "pastry dough cutter" type handle than the same type with the vertical stick handle.