I was heavily into burning DC ROMs back in the day. Its most valuable utility was making backups of the games we owned, as our first copy of Sonic Adventure 2 became scratched and nearly unreadable after awhile. The backups allowed me to keep our "critical" games like Soul Calibur, MvC2, and Power Stone 2 (that one cost a pretty penny) in their cases while we used the backups. It also allowed a handful of custom soundtrack-editions of games to float around on the web, like one which changed MvC2's (IMO, awful) soundtrack.

One thing I lament in hindsight was that the CD's we burned were not GD-ROMs, and so the backups or ROMs we burned often had their assets compressed in order to fit on the smaller disk.

Further pity is that even 15ish years later, many people in the ROM collection scene are still relying on those early, compressed CDI rips that were made over a decade ago. The higher-fidelity GDI dumps are comparatively rare and hard-to-find, especially with such reliable repositories as Emuparadise shutting down. If I had the proper equipment, I would probably try to make proper GDI dumps of my collection.