i have a Pfaff 2036 and have had for a while. It is most finicky.
I recently changed the thread from a rayon I was using to FMQ to Coats and Clarks (without thinking). The poor thing just threw up. It absolutely hates Coats and Clark thread. And not too fond of Gutermann either. Which leaves the more expensive threads.
I have apologized to it and set it aside for a little bit.
Why do I bother with it? When it is sewing there is absolutly nothing like it . The IDT guides the fabric smooth and straight. It hums and purrs and does beautiful fancy stitches.
If I could find a good used Pfaff with IDT I'd buy it in a minute(for the right price!).