I use mine on the Bernina all the time. The one on my Elna is very good. I have a small Janome 3160 QDC, I love the machine's sewing, BUT the automatic threader is a pain, it doesn't work well, and this past week it actually fell off the machine! I put it back, but am thinking of just ditching it.
The size of the machine needle hole is also important. Hard to work with a tiny hole!!
I want a machine that REALLY automatically threads the machine....and then automatically sews my piecing,...and....and ............aha......what a dreamer!