As the article you link to says it originates from my home country and has been used here in Europe since the seventies. I used it myself on several cars with very good results, it's easy to work with and it's always a good feeling to put something under your car that you know won't corrode.

Regarding this sentence in the article "The Cupronickel alloy is softer than steel and so more subject to damage from rocks and stones being kicked up from the road than steel." my comment is that I do not route brake lines inside the wheelwells where this could happen anyway. On rally cars that's raced on a lot of gravel and dirt roads they usually put as much as they can of the hard brake lines inside the car to protect them.

Interesting, a question ... does one still need to double-flair the connections when using Cunifer tubing?
It is my understanding that the double-flair is required to get a good seal due to the pressures involved in the braking system.

You can still run DOT5 with Cunifer right? My car will be getting 100% new brakes, lines, calipers, etc. So I might as well do DOT5. So for someone starting from scratch and knowing there will have to be some custom pieces the ease of working with Cunifer sounds attractive.