Of course you don't need to use compression, but you're right about indexing. Can take a long time when needed, which is every once in a while even when you're just playing spots and liners. And defrag isn't something you can do without taking the system off line for 30 minutes.
Digilink was a great product in its time, and some of the operational features have still never been duplicated in any current windows-based system (including their own Digilink Extreme). But multi-station clusters can't live with the labor-intensive dubbing and lack of ability to use a server for the audio files.
The Digilink III had more features than the II, but was not as stable in my experience.