Today I did SID for the first time in about 6 months. I was surprised at how good my stitching looked, especially since it had been such a long time. I think my success was due to the fact I went slowly, used invisible thread, and used an open toe walking foot. I have a foot for my walking foot that has the metal guide down the middle; but I do better with the open toe foot. Oh, I did have my quilt well supported by tables and I wore my quilting gloves. Tomorrow I have to do the FMQ on the quilt. I'll probably feel like you did doing SID. Best wishes with using the serpentine stitch if that is what you decide to do.