What about showing (or optionally showing) agent calls/call time per day?
To elaborate:
On running a custom report for an entire month, a manager can see how many calls were answered/unanswered per day, the avg. wait time per day, the distribution per hour, etc... something the Director of Ops here pointed out that would be rather useful is the ability to break it down to call-time per agent per day without having to go in and individually select each agent (not such a problem if you only have 10 agents... but what if you have 100?).