A little late to the conversation, but was looking for ideas for a new machine with a larger throat. I have a Jazz and took it to a repair guy to be fixed because it was doing the same things that everyone was talking about here. The lashing and just general poor stitching when trying to free motion. He told me that one issue with these machines is poor design. The issue is usually in the needle bar. The frame that holds the needle bar is aluminum and the needle bar tends to get a little sloppy. He said he could work on it and get the dropped stitches to stop and for it to work better, but he couldn't guarantee for how long. So I think I will just bring it home and try some of the things mentioned here. Maybe something will work. Hopefully.
But I do think I am going to look into an industrial machine. I watch Donna Jordan a lot and she uses a simple Juki Industrial and I am doing some research to see how well something like that would do for free motion quilting. I know that there are several Juki home machines that are designed for quilting, but do not have a very big throat. Any ideas?