I think it's great that there is a burgeoning variety of music apps on Mac OS, but I have to say... I find it impossible to tell a difference between any of them.
Maybe it's my system? Maybe I'm doing something wrong, or maybe there really isn't a difference. Bit Perfect = Bit Perfect, etc etc. Of course, I would like to be proved wrong - I simply need evidence. Expectation bias appears to be rife when dealing with these types of things, and anecdotal evidence appears to be taken as truth all too often. If you download the hottest new audiophile music app expecting great things, chances are, when you look for differences, you will find/conjure them.
I'm perfectly happy with Vox. It's free, lightweight, and I love the interface.