I agree with Dj_AmTrax.
But also with OS in 32bits and installation from scratch with Amarra 2.1.1 I had small drop-outs every 2-3 minutes during playback. I checked the activity monitor and found every time when a drop-out occurs network activities. I disabled the network, but the activities (and some very small drop-outs) remain until I unplugged the network cable (I already have deactivated Airport). Now, with all network activities disabled and the network cable unplugged, I have no distortions like drop-outs anymore.
Another point: for the update of the track display in the playlist window, it is important that the filename has max. 30 characters (There is a remark about the lenght of folder names in the FAQ "My song does not play", but about my experiences it is also valid for filenames, and there is also a remark in "known issues"). Otherwise the track display will not update and the playlist window shows always the same track title. If I use a saved playlist, the display update does not function too. I have to drag and drop the tracks in the playlist window.
But: The sound of Amarra 2.1.1 remains for me still better than Pure music and AyreWave.