Originally Posted by thepolyparrot
The 401 is my sentimental favorite, but I like sewing with the 403's and 503's better, too.
The look at the guts shows the main reason - the 403 and 503 aren't as easily gunked up and frozen as the "top of the line" models. :)
You are right the 403 and the 503 don't gunk and freeze - not at the stitch selector since they don't have one.