I've used it in my Bernina and have had really good luck with it. I haven't tried it in the 301 yet because I started a piecing project with gutermann. I tried use the aurafil and there really is a difference. My 1/4 inch seams were much smaller and seemed to lay flatter with the aurafil. After this project, I"m trying aurafil in the 301. It will probably be my go to for piecing.
I'm surprised you had problems with it breaking when it worked in my Bernina. My Bernina is usually the machine that thread breaks in if I don't remember to reset the tension. Bernina's seem to come with the default tension settings pretty tight.