Keep in mind that the upperend Janomes do have some issues in finding the perfect setting for a 1/4". Because this is important to you I thought I'd throw that out there.
I have the 6600 and I enjoy it ,but I did have to fudge with the settings even with the 1/4" feet. I did find what I wanted and consigned it to the machine's memory . That makes it easier and now it's no trouble.
Someone noted that the Janome feet are difficult to attach and I agree. I switched feet about 5 times yesterday and each time I dreaded it--but got better as I went. I have another Janome so they are similar set ups but they did no one any favors with the newer ergonomics of the machine.
You're going to get 20 different answers here. Lots of wonderful tools for our craft out there. For me, I was drawn to Janome because my old machine was a reliable workhorse. So far, I'm not disappointed but there are a bunch of great machines. Good luck and happy sewing.