I have the Janome Horizon 7700 -- it has the accufeed and is a great quilting machine. Before that, I had the Janome 6500. I also have a Juki on a frame. The Juki is just a straight stitch while the Horizon has a lot of fun stitches.
You were looking to have both a sewing and quilting machine -- when I bought the 7700 I had been looking for one machine that would do both, but the harps on the embroidery machines were smaller than the 11" Horizon harp and I the 6500 had as small a harp as I wanted. Once I saw the big harp, the extra lights and the free arm, I just got the Horizon. I have had it over a year and it is doing well.