They are nice. They are protected. I love mine.
That being said, I would have to say that fresh proper lines will be just fine and will last many years and for thousands of miles at pennies a foot.
Anyone out there who cannot confirm the age or condition of their lines could save some major, and I mean major, headaches by replacing these lines, especially if you have done oil pump work where you have renewed the oil pressure. My system reads 90lb's cold at idle and 75 hot down the interstate. If you plan any trips, reinforced lines should be concidered or at least have a length of line strapped to the frame under the seat.
1972 Norton 750 Commando Roadster