I have a 600 model. The 600E was a change in the bobbin winder mechanism. My 600 has to be manually reset after the bobbin is wound, the 600E automatically reset. This is one of the last all metal gear machines Singer made, but one of the first wind-in-place bobbin machines. It does take getting used to. The machine itself is very similar to the 401 and 500 machines, but the main difference is that bobbin winding design, bobbins and the bobbin case itself. I don't especially like the fact that the bobbins don't hold that much thread. It does sew as well as my 401, 500 and 503. Hope you have fun playing.
Pat