The 4000 model I got recently was outstanding. But a Dremel is just a Dremel without the flex attachment. Now you have an almost pencil thin tool that gets into really tight places. I thought the 90 degree attachment was going to be my favorite, but nope.. the flex tool is really the big improvement. The 4000 kit I got had all of the attachments included. In any case, its a step up from my 70's model that died recently.