I have used both, and also the recently released jRiver Media Center Alpha build for Mac. I also recently downloaded Audirvana Plus and started playing with it. They all have strengths, but I think I've about settled on Audivarna Plus. It allows iTunes to handle my entire music library, including formats like Flac, and that means that you can use Apple's excellent Remote application to control the music and playlists. It is also really simple to set up and use.
Just one Person's opinion. YMMV.
Just one Person's opinion. YMMV.