You will probably never use the free arm so take it out of the equation. I have a Kenmore made by Janome and I have had 2 Brother machines given to me (my friend is a thrift store haunter and she knows I like sergers). I love both brands. The Brother was a dream to thread, my Kenmore is not hard but, they didn't make it nearly as easy as the Brother. I have taken both brands of machines apart (Removed the outer plastic covering) to clean and oil them. My Kenmore because it was really dirty and the Brothers because they needed cleaned and were given to me so I figured nothing ventured, nothing gained. Both machines are made of all metal under the hood and not cheap pot metal. I didn't see any one area on either machine that I felt would fail before the other. The knobs/mechanism to change stitch length and differential is plastic on both machines. If there is a weakness that would cause a failure in the machines this would be it - 20 years from now. If you take care of the machine you buy you will have it for many years. Janome and Brother are both good machines and I would buy either one. I kept my Kenmore because I paid for it, the Brothers both got rehomed at no charge to young mothers wanting to sew for their littles.