We've been using DL for years at home where we have copies on several machines all accessing one shared data folder via hard-links. We have to be careful to have one copy open at a time, but it's worked well with only one case of corruption at the beginning.
It looked like one of the features in DL2 was going to be built-in sharing the database, so no more hard-link kludges. Turns out I misunderstood - not only is the "sharing" more like publishing a document in the System7 days of OpenDoc (and thus not what we're looking for), but the new faster "true database" back end does not like to be accessed as a shared volume, so we can't even use it like we use DL1.
After several email exchanges at the height of DM's DL2 support flood, we finally mutually figured out that what we did with DL1, DL2 could not do so our purchase was immediately refunded and the network-share database feature was put into the wish-list.

'Till then we're happy with DL1, even though we had to split it up into several separate data folders - one for movies, one for books and one for audio.