I do have a tip if you are trying to use it to backup large virtual disk images.

Use snapshots to stop the vhd from being updated all the time. I keep a snapshot running, so that CP only has to scan the smaller snapshot file.

Every couple of weeks I merge the snapshot back into the main file, at which point CP has a few hours work to do to scan the vhd, but at least that means that on a daily basis I get to have a current backup of the image without CP spending hours each day processing a massive file.

I'll guess that I'm not the only person out there doing their Windows development in a 50GB VM on OSX