The new Janome 1/4" foot arrived in my mail box today. I've been eager to get it, so I opened the package and compared it to the original. No difference from the top view.
The new foot is on the left. The groove should provide better control going over seams. Will have to take it for a test drive and report back. If you own a Janome Horizon and got your new foot, I'd love to hear how you like it. :)