They both have a life expectancy of over 20 years. Vinyl tends to blow off in windy areas and sun fade. It shatters on impact when it gets older. That has been my experience anyway. Fiber cement has only been popular for the last 25 years and I haven't worked with it personally. I do know that it's rigid and takes special tools to put up. It's also flipping heavy. The maintenance guy in me wants to say vinyl thinking of future repairs.
