I have a Janome 10000 upgraded to the 10001 and it has the start/stop button and I dearly love it. I will admit it took a little getting used to it, but now when I sew on one of my other machines I am always trying to start and stop it with a button and the button isn't there on the other machine. Use it continuously for two or three days if you are doing a lot of sewing and you will get used to it.
It's kind of like getting used to a thimble. I could never wear a thimble and a quilting teacher told me to put it on and wear it around the house for three days and I would be able to use it. I had by doubts, but decided to try it and it worked, now I can't even embroider without it hardly and I never used to wear one at all.