I have been using PureMusic for quite some time now. I really like what it does for computer playback.
Having said that, the latest barage of releases to deal with iTunes 11 is a complete joke. They are on 1.89d now, and this release still plays the first song in my library upon startup, no matter what song I select. It froze up and I had to restart the computer to fix the freezing twice. Additionally, I can no longer toggle from non-upsampling to upsampling. If I do that, playback stops. I then have to quit PureMusic and restart it. Then it is in upsampling mode. It works without issue going the opposite way (upsampling to non-upsampling).
Are they making changes and letting the public test them? They seem to be making changes on the fly and hope they fix issues, only to create new ones.