The reason I asked that question was because I am looking at some Pfaff's on Ebay, and I can't tell if they have IDF/IDT (whichever it is) or not. The description doesn't say it and I don't see that arm that comes down behind the needle bar in the pics.
So I was thinking that maybe some of the lower-end models might not have it.
Thanks for all the info...it's sounds like maybe the one I'm looking at doesn't have it if there is the option of not having it.