I had the 6600 for about a year - bought for quilting. Didn't do much quilting so really never used. Used my Janome Jem Platinum for pieceing and small quilting - love it - expecially for classes. A LQS was having a demo on the Horizon, so I went just for curiosity. I traded my almost-new 6600 and bought the Horizon - which had a lot of new features that I liked - convertible plate so no need to buy single-hole plate, wider sewing bed than the 6600, better lighting, more memories to store frequently used patterns, feet can be stored in the machine's "holders", top flips up to show stitches instead of screwed-on stitches plate, and to top it off it has a red panel on the right (my favorite color) and a cat design as one of the special decorative stitches (I love cats). Plus I'm getting 15 FREE lessons (cost $60 each). I was sold! I have several friends who have the 6600 and absolutely love them. My advice would be to try to save up the extra money for the Horizon, otherwise the 6600.