i noticed that some folders in the organizer were taking a long time to load, many seconds. i then turned off the torrent client that was saturating my connection, and the folders loaded immediately. possibly microsummary loading?

likely just disk I/O in general (most of the library still uses synchronous I/O)

there's no direct fix for this, apart from reducing IO, for which we already have covering bugs, so resolving this as a dupe of bug 490714