Claim:
I believe MC should better support playlists that are kept externally. Instead of import/export capability, MC should keep external playlist in sync. This is basically treating playlists as objects of the database (like mp3 files) and keeping information in the external files and database in sync (just like what MC does for the tags)
Problem:
Reliability
Based on my 5-6 years experience of using MC, tags are usually more reliable than playlists. You can delete your MC database, i.e. while trying the latest beta. The playlists may disappear but the tags are stored on the files and can be restored by reimporting. (fine you can backup playlists, but how often do you do that? Also, how do you search through 100+ backup files if you don't know when the playlists are lost)
Sharing
Currently, I don't know an easy way of sharing playlists created by multiple users using different databases on different machines. Sure, you can export and import playlists but that is difficult. In contrast, it is relatively easy to keep the tags in sync when they are edited by multiple users. This can be achieved by keeping the music at a shared location and people setup MC so that tags always override MC database. Playlist data could be shared the same way, if MC could keep external playlists in sync.
external applications
Storing playlists externally could allow creative solutions by using external applications to manipulate playlists. Notice that this can already be done for tags.
How about smart lists?:
How to store them externally might not be as easy as the regular playlists but that would be great for sharing smartlists and for backups.
Summary:
MC should support the ability to keep playlists in external files. All MC would need to do is to keep the information in playlists in sync with its internal database, just like as it does for the tags.