Huge fan of Redis here :-)
Its latest version adds the following:
- Access control lists (ACL) so that clients/users can be barred from performing dangerous operations
- Multithreaded I/O (Redis until now has been largely single threaded with async) which is bound to make Redis even faster
- Client side caching: this is really cool in my opinion, reminds me of the evergreen article about how StackOverflow does layered caching
- Longest common substring (LCS) command which works both on text and binary data
See Redis Labs: Diving Into Redis 6.0 and the official release notes.