PokerTracker

Hi all,
I see that the HUD stats update whether or not the hand history text is saved for observed hands. This being the case, can someone please fill me in on the pro's and con's of storing the hand history text for observed hands? In other words, do most of you hardcore dataminers keep the hand history text, and if so what do you use them for? If not, why not? In other other words, what am I giving up by not saving them?
Thanks,
Freeze

The hand histories are required for the replayer, as well as for in the future if the database schema changes dramatically and hands need re-imported.

Thanks!