I'm finding MC13 to be SLOWER when working in the database to review and update tags. My database is more than 80-thousand tracks, and the view I work in has lots of fields and many virtual records. But this is all the same as I used in MC12 where playing/editing response did not degrade as much or as quickly (MC12 could get slow too...). I'm using the same computer, lots of CPU, RAM, disk space, etc.
Scenario: I rip a bunch of stuff, then work through the tracks, listening and tagging. I'm sometimes in Recently Ripped, but often I switch to an Artists view so I'm comparing the new rips to all my other tracks by the same artist. While I might have just a few dozen tracks by a particular artist, overall this is a very large view, larger than my total database because a track that is tagged with more than one Artists name (a custom multi-value field) will appear more than once in the view -- virtual records.
In MC 12, moving to the next track was fast. Click, listen, tag, move on. If would get slow eventually, usually after MC sat open overnight (previously reported oddity). But in general I didn't feel constrained in working quickly.
In MC 13, as I continue to work, delays build up and eventually there's a many-seconds delay before the new track full loads. It starts playing quickly, but the tags open more slowly, and the playback info at the top of window opens VERY slowly. I use this part of the display to scroll through the song, checking different aspects, and to quickly see the sample rate and stereo balance. But it sometime takes quite a while for this info to fully populate/update before I can use it. The playback duration/position bar is usually the last element to update, 10 to 20 seconds after the song starts.
Performance is OK when I first open MC13 and start the above process, but after a while (10 minutes?) it gets slower and slower. If I close and restart MC I get back to good performance, for a while.
A wild guess is that updating the database/view is given higher CPU/memory priority than updating the data display of the current song, presumably because MC13 is optimized for navigation/playback not for database/view editing?