The Serenade has 9mm stitching the Horizon doesn't. I'm not crazy about the huge Accufeed foot on the Horizon, vs. the nice (and small) dual feet foot on the Babylock. Personally, it would be very hard for me to buy a machine I couldn't test drive for $2,000. I'd search your neighboring state for a Babylock dealer to test drive BOTH machines. The harp size does matter, but I don't know where you're getting 7" for the Horizon...are you meaning from the needle to the arm?