Does anyone have experience running data intensive VFP apps over a SAN?

If so, how does performance compare to direct-attached HDs? I've read that SANs can be set up with impressive IO capabilities by spanning LUNs, thus giving IO functions multiple disks to read/write to. But there is also the question of latency and network speed.

Can SANs be faster than direct-attached HDs?

What aspects of a SAN should I be looking at when evaluating performance (i.e. switch speed, etc.).

Thanks,

David