Regarding the long bobbin, I actually think it has a lot to do with what you get used to. Class 66 bobbins takes a bit more thread, and doesn't have to be wound that often. There are ways about it, like winding a few bobbins in one go and keep in mind they have to be replaced at shorter intervals. Model 66 was an innovation when it was introduced, with a drop in bobbin case for easy replacement of the bobbin, but replacing a bobbin in a vibrating shuttle case is not a big deal. Before model 66 it was either a vertical bobbin case like model 15 or the vibrating shuttle like model 27. I know someone who swear their model 28 is the best machine they have for perfect and precise stitching. Model 27 is as I'm sure you know the large version of model 28.