I don't think you are overthinking the issue--I think you are being wise. I was in your position this time last year, and researched thoroughly before buying. I already had a Kenmore (made by Janome) that had served me well, but wanted an upgraded machine with more bells and whistles, and one more conducive to FMQ. After extensive research, I decided on Janome...and narrowed it down to two machines--the 6600 and the 7700. The 7700 is a great machine, but it would not fit in my cabinet (which is perfect for my studio, and I didn't want a new cabinet). So I got the 6600 AND got a 350E embroidery machine. I was able to get both machines for slightly more than the cost of the 7700. The extra 2" of harp space would be nice, but I haven't had any problem with the 6600 (in fact, I made king-sized quilts with my old Kenmore, which has much less harp space than the 6600). The free arm was not an issue for me since the Kenmore has a free arm. All in all, the 6600 is a wonderful machine, and I am thrilled with it...and with the embroidery machine. Good luck and happy sewing/quilting!