Well I might as well put in my $.02 ,we have been selling these portable machines w/a walking foot to alot of inmates for sewing leather crafts,in alot of the prisons they aren't allowed to have a industrial machine w/a large table so these work for them they come in 7 & 9" arm length w/straight stich & zig-zag.
They have a 1.5 amp motor vs a 1 amp motor on a reg home machine,they also have a cog tooth belts,like a timing belt on a car that doesn't slip.
Along with a little speed reducer that give it the punching power.
We even have an old machine (mini-walker)we use as a rental for people to sew upholstery with.Very easy to handle for them too!
They aren't the greatest or smoothest machine I've ever ran BUT they get the job done @ a low price.
Bob