I'm a big believer in fiber. When I was at the University of Maryland about eight years ago, I rewired the university with fiber. We put fiber in every office, classroom, and laboratory, making the university the world's largest fiber installation. Unfortunately, the University of Maryland is probably still the world's largest fiber installation. Fiber for local wiring has not yet taken off.
Electrical connections are much less expensive.
Even so, I would install fiber for backbone connections because weare nearing the end of copper bandwidth charts. With Gigabit Ethernet, we've extended copper capacity farther than many people thought possible. But we are just beginning to tap the bandwidth that can be accommodated over fiber. So I'd rather run on fiber at a lower rate than fiber can accommodate, knowing that I can upgrade to higher speeds. It depends on what they're currently using and when they installed the cabling system.