MM is truly excellent at playing back every file format (mine library is mostly MP4/MP3/FLAC-APE) with support for many addons to increase the already impressive functionality available - its so simple Ive stuck with them for years! For my own CDs I rip using EAC in FLAC format (perfect quality) and manage music using MM. If you rip CDs with MM you can use Auto-Tag from web (ALT+L) to automatically name your tracks with covers & information.

I love listening to my music library (cheap £500 10TB microserver) on continuous shuffle when Im back from a hard days work, it manages huge libraries effortless and plays music back instantly. My existing playlist is currently 6000-songs strong and counting.

FYI I use MM Gold. Tip for iPods, etc, you can configure non-compatible formats on the fly but make sure you manually choose stereo (Options> Portable/Audio Devices) as otherwise it will default to the lesser joint-stereo - worth sticking to 320kbps mp3 for connecting to car systems.
I make sure MM uses my SB Audigy soundcard for hardware acceleration and its crystal clear with no stuttering, even on 4500kbps 24bit/192KHz FLACs.

I use this to burn all my images (backups), and to create copies of my own family home movies from either BD or DVD when they watch it and want one done for themselves. Very easy to use!