Is anyone really using the Message Tracking Collector?

MTC indexing puts a big hit on your Domino server's CPU usage and doesn't provide results when I try to run reports against the data, most of the time.  That said, I find it to be an easy way to verify that user A sent a message to user B, who deleted it.  I also like the ability to issue a tracking report right from your Sent folder.  I could really use those reports on message volume and top senders also, but even if I run it against a single day of data, I can usually expect a blank report, or one that says there was too much data to process.

Is there a known upper limit to the volume of mtdata documents the report tool can process?  

Further has anyone found a sweet spot for the number of minutes to configure the collection interval in the configuration document?  I've tried longer collection intervals (2 hours) so my CPU doesn't ramp way up repeatedly, but then I find events in DDM indicating it can't keep up with the volume of data.  I've tried short intervals (the default 15, 5, etc), but I get the same message?  

I don't find a lot of feedback from users on the forum, nor useful documents in the KB about these issues, so I figure noone uses it because of the issues I face, and IBM gave up on it from the get-go.  True?  What other tools do you use besides normal statistics collection to create the kind of reports that the MTC data and Reports database can (potentially) provide?