The --cache option does not take a number anymore. (Oh boy, this is
going to break a lot of user configs?)
The cache site is now configured with those obscure-sounding --demuxer
options.
--cache-secs is not useful anymore. The default is very high, so the
obscure-sounding --demuxer options determine how much is cached.
Advertise the --cache-on-disk option a bit. I found it useful once, and
it will trick users into wearing out their SSD for no gain, or so.