OK, finally had a chance to try this: just used a playlist (all I really need are the new songs, and I made a smart playlist based on date added to get these songs [copied those to a manual playlist that I then exported]).
Procedure:
- exported playlist on laptop to XML file on laptop
- copied songs in playlist within iTunes (view playlist, select all, right click and select copy)
- then in Finder pasted the copied playlist songs to a new folder on laptop
- on desktop did a Add to Library to add songs over network from playlist folder on laptop (from prior step)
- on desktop did a Library->Import Playlist and imported playlist XML file from step 1 (over network)
(One observation: some of the songs were purchased from iTunes: at first I didn't realize why all the songs didn't get imported into desktop library in step 4; then I realized they were already there on the desktop because they were purchased and the desktop and laptop have the same iTunes account ... so a purchase on laptop automagically appears in the desktop library!)
RESULT:
Sure, the playlist got created OK, but key metadata seems to have NOT been copied over, e.g. all my star ratings except for two songs were not copied over.
Example: one song had a 4 star rating and sure enough an XML entry "Rating80"
...but it came out in the desktop library with NO start rating.
Time for some manual updates ... and a better procedure! 🙂