The JRiver Release Notes have a complete list of all changes made to JRiver. You can browse the notes and search on "new:".
https://wiki.jriver.com/index.php/Release_NotesI find that there is a feature or change almost every week that I like. Some may seem insignificant, but they add to the enjoyment of JRiver. Others are more major. The new tag action window was added in MC21, but was expanded and refined in MC22.
Here are a few changes:
NEW: The SoX resampler can be enabled in Options > Audio to handle all your resampling needs.
NEW: "Panel" which is a new web interface. Take a look at
http://localhost:52199 (or whatever port you have configured in 'Media Networking').
NEW: Added "Options > Audio > Load files to memory at the start of playback" to totally load a file into memory when playback starts (works with APE, FLAC, MP3 -- others to follow).
NEW: The DLNA server Audio Advanced DSP studio is active for all functions including sample rate changes.
Changed: Scrolling the new tag window will stop any open edits (instead of scrolling the edit off the screen!).
Changed: Updates for pretty much all the skins (thanks Awesome Donkey!).
Changed: Added a couple extra checks to Monkey's Audio to detect (and hopefully handle) corrupt files.
NEW: Added the memory playback mode "Load full album (not decoded) into memory." Loads the entire playlist (up to 15 tracks) into memory.
NEW: The new tag window has the ability to show all fields with values (just add the type "Fields With Values" in the edit dialog).
NEW: Added "Stop After Playing Track" to the right-click menu in Playing Now.
NEW: Sidecar file support for audio, data, image, as well as video files.