I've never used it. I think the max servers I've had is 10 hosts. but some of those were free version and some the paid version so it's never really been feasible for me.
IOPS are the biggest concern really. But without anything like a database which really needs them, RAID 6 might be more than enough. Exchange wouldn't be a big concern as it is not IOPS heavy. RAID 10 is far better tuned for heavy writes, but if reads are the vast majority, RAID 6 will keep right up.