For all intents and purposes, I have one machine that I use. A Bernina 1008 Mechanical that I have converted to treadle. I have 2 more in storage if that one gives up the ghost or if I can no longer get parts. I also have a 221k Featherweight that sits there and looks pretty, and a Singer 404 Straight stitch, that I never use. So. The answer is, Bernina 1008 Treadle for every type of sewing I do. I love it. Here is a link to a picture if you have not seen it.
http://www.quiltingboard.com/t-150099-1.htm
John