What information are you specifically looking for?
We use Crystal both stand-alone and as part of our BO XI system. The stand-alone reports are one-time, I-want-the-data-right-now type reports where we don't care if we have an historical copy. The reports that are in BO are reports that are scheduled to run at a specific time. We keep the historical "instances" of these reports for research purposes. Frequently these reports are on a regular, recurring schedule so that the users don't have to actually "run" them, they just go in and open the report instance from a specific date and time.
-Dell