I have used a Mac for the basis of an audio system for the past 6 years. My current configuration is a 2010 Mac Mini with 8GB RAM running the latest version of Mac OSX. I use iTunes as my library manager. My library resides on a 2TB external HDD with a second daisy chained via FireWire 800 as the back up. The majority of my library (1700+ albums) were imported from my CDs with less than 10% (but growing) being purchased high resolution downloads. I use XLD with AcuurateRIP to extract AIFF files from the CDs to my library. I have used several playback softwares which I find exceed the performance of iTunes and provide additional beneficial features such as auto sample rate switching. These include Pure Music, Audivrana +, Amarra and now JRiver for Mac. Audivrana is my preferred player of choice for now. Long term, as it continues to develope JRiver For Mac may be my choice because it is not only a player but a complete media management system that replaces iTunes. I output this via USB to a T+A DAC8 and then to Dynaudio Focus 110A powered monitors.

I don't thing I have ever been happier listening to my music based on the quality of output, accessibility and functionality.