I'm using my 99k to make Bow Tuck bags, in place of my featherweight which I use for piecing. The featherweight works for sewing the bags but I was worried because of the heavy work. The motor on the 99k seems about the same size as the FW. The bigger machine is heavier-built, seems sturdier. I don't know if the 99k is really stronger but if I do burn out the motor it will be easier to replace than my FW.