I'm a huge fan of the mechanical drop in cam machines whether Kenmore or Singer or what ever. I like my Singer 403 the best, then the Singer 503 - The Singer 401 and Singer 500 do have the built in stitch selection but you get more width control with the drop in disks. the 403/503 are simpler and easier to maintain. I prefer a wheel I can grab hold of when I hand turn. As far as which is better I've seen that it varies from one machine to another. The 500 and 503 are very kool to look at. The 401 and 500 are a lot of fun to play around with no matter what. I really don't think you can lose unless you get one that is all stuck up and not moving. You do want to have a full set of disks with the 403 and the 503.