I have had the Viking ruby then traded it in for the Diamond Deluxe. Love both machines. Not picky, self adjusting tensions, I've never had to adjust it, ever. One small repair,
I'd do it again.
I think its always good to have a backup just in case but don't feel it would be something I'd go out and buy. I had a Kenmore/Janome and it works great. I recently won and then traded up a new Brother that does Disney designs and that will be my backup. Here, with Brother if it has a problem they fix them on site but I can't imagine having two go down at the same time. My daughter has always wanted my Kenmore so now its hers, and her Singer I'll give to my daughter in law. My brother also has self adjusting tension, as well as my Babylock serger,this makes life so much easier.