I have the Janome MC6600. I love it. I use it all the time AND I use the knee lift. The AccuFeed is great for so many applications. I really like it with flannel because I don't get the distortion I do on other machines - and I have several.
I have finally mastered the needle threader and use it all the time but I have to say it is a major disappointment after my Babylock Ellegante. I bought the Janome so that I would have something with a larger harp to sew on while embroidering. The BL has nicer decorative stitches but the Janome sews faster (probably why the BL stitches are nicer!) and it sets in a recessed table. I am kind of short bodied so that is better for me.
The one feature I don't like on the Janome that most people would love is that the lights are too bright. Sometimes I just have to switch to another machine.
Yes, I would buy another and I use most every feature I have found.