Groovy. So are you running a daemon on the apple server, and some kind of client on the Pi, or both on the Pi? I thought you'd mounted the music share on the Pi is all.
Have you checked out RaspbMC? Does video and photos as well (rather fine) as a development from XBMC (X-box media centre), nice library, phone / web / remote control etc.
C
I have MPC (client) and MPD (server) both running on the Pi.
I did originally have all my music running off the Mac (using Audirvana+ as the player) and I can still use it with a USB connection to my DAC, but frankly the Pi setup sounds better. In many respects it shouldn't do, but it just does, so I'm sticking with it. I'm guessing it might be partly to do with the simplicity of the Pi circuitry and associated power requirements.
RaspBMC is an excellent interface, and was my first choice. But it would not work on wifi for me (it's a known bug, which nobody has rushed to fix). Also, you cannot get a command line session up from the default interface. So you are reliant always on the UI config. This to me is kind of against the grain of Linux. Yes, you can open an SSH session remotely, but if you can't get a network connection in the first place then you are stuck!
I still have RaspBMC on one of my SD cards and have ordered a different wireless dongle, so will retry as the interface is really very good.
I've tried about 4 different flavours of RPI-oriented operating systems, including at least one audiophile-oriented version, but i have stuck with Raspian since it seems stable and functional. I actually never perform updates, since I wasted a day or two recently trying to work out why my movies were no longer displaying on OMX player, only to find out eventually that the latest OMXplayer build is faulty. Grrr.
FWIW, my set-up sounds very 'analoguey', however the monitors (LS50's) paired with the Cyrus 8 leave the sound a little bit on the thin side. Not sure how to add more bass. I don't want to dump the speakers so maybe the amp needs changing out. What ever happened to tone controls?