It is very nice to work with. You can form it by hand. The double flaring tool works well with it and the flared ends produced with it seal correctly. I prefer it over plain steel. I don't think I could accomplish anything with stainless tubing. The nickel copper tubing also looks nice and does not corrode.
I was at a shop recently that specializes in hydraulic brake and clutch lines primarily for racing applications. He said he only works with stainless because that is what his customers request.