Got this last month, I like it, but there are a few strange things.
First off - I have an older Pfaff, and like a lot of Pfaffies, we did almost everything in classes - including adjusting tension, bobbin tension, dropping feed dogs. Thread painting. If it was possible on that machine, we did it.
That said - the 1500 has the same type bobbin case. I took mine out to change thread color, and the tension was loose. If I picked up the bobbin by the thread, the bobbin just slid down. This has happened twice with 2 different Brother bobbin cases. Does the machine vibrate them loose? The Pfaff stays put.
How far down do the feed dogs go? Even when on the lowered setting they must still be up a bit. I covered the feed dogs and used a slider. There were marks on the back of the slider where the feed dogs hit. They were lowered.
I can feel a hitch that I can't find in the threading. Aurifil and Prescencia curl like pigs' tails. The stitches look as they should, balanced, but coming down from the takeup lever, the thread is curled. I've used all these threads on the Pfaff, and nothing except clear thread has curled like that. I can feel some resistance like a burr somewhere when pulling the thread from the needle with the foot up. I have an upright spool holder on the Pfaff.
I don't want to have to return the machine - if there is an easier solution I'd appreciate it. The machine is threaded as in the manual, since the Pfaff uses the same bobbin system I have no trouble in remembering which way the bobbin goes, I wind the bobbin slower than most and make sure it is filled evenly. The machine is cleaned and oiled. I've checked everything I can think of except flossing tension disks.