I have the Horizon and am (now) very happy with it. I did, however, have a rocky start. My original machine was just a lemon, I guess. I had several major breakdowns in the first 6 months that I had it. Finally, I wrote the Janome and they arranged for me to get a replacement unit. No problems since!
I love the large throat and the extra lighting. I just recently did a quilt with a lot of metallic thread and different stitches (FMQ and built-in patterns), and it worked great. I do wish it was easier to change the accufeed feet.