Other things currently missing (or less robust) on Linux:
1) Cannot open files in an external program.
2) No integrated web browser
3) No loopback or line in of any kind.
4) No cross platform filepaths, which has implications for client/server setups (e.g. so you won't be able to play DVDs in .ifo format on a client).
5) Very limited Data file support (works for server, not for client)
6) No native DSD playback (only DoP) (this is a limitation of the OS not MC, Linux has no equivalent to ASIO which is required for native DSD playback)
*7) Start on boot checkboxes do not work (you'll need to script auto start if you want it).
*8 ) Related to incomplete video support, the on screen display for video is currently broken. Playback works, but it can be hard to use the OSD controls to pause, skip ahead, or stop playback. Keyboard shortcuts work fine.
There are more, I'm just trying to recall them all (I'll add them as I think of them with a star to indicate later additions).
Also, let me know if you plan on using MC for Linux as a server in a mixed windows and Linux environment. There are some "tricks" you can do. For example, MC for Linux doesn't support theater view, so won't let you edit views for theater view in its interfaces. But if you backup a windows library and import it on a Linux server, the theater view customizations you made on the windows library "come through" and the Linux instance will faithfull serve them to windows clients. Stuff like that.