Not sure to be honest. I was grouping the players according to their intended purpose.
You can switch this off in the preferences. Also, if you hide the application, it only shows as a tiny line that floats across iTunes to indicate that it is working.
how long did it take Fidelia to load the Itunes Library in your experience? For me it just disappears and never comes back in the process of loading it... Seems to be very buggy...
I like Vox for the implementation of AU plug-ins. Would like that feature for Decibel too
The first few times I used it all sorts of things didn't work, now it works fine. I suggest not starting it up if you have any of the other music players open, especially if they are in interface "hog" mode. I found using Decibel in hog mode would cause issues with Firefox because presumably flash couldn't access the audio interface.
Presently my favourite for sound quality is Fidelia using iZotope up-sampling and Dither. That's specifically for my system though, tested with a lot of Chopin to see which gives the most realistic piano (to my ears).