I just installed the new 1.0 update; all is running perfectly so far. The new version preserved all of my settings from the previous version, which was nice. I went through the new manual, and made some changes, setting BitPerfect to all the recommended settings.
I've not had any problems with any previous versions, probably due to the fact that I use a Mac Mini dedicated only for iTunes music playback, and it has 8GB of RAM. I've never had any of the often mentioned track stuttering or skipping, or any glitches at all.
I use the Wyred4Sound DAC-2, which doesn't support integer mode, so I have that disabled; I plan on experimenting with the I/O Procedure Duration and Thread Priority sliders a bit; I've already tried moving them one notch to the left each. I'm not sure I notice an improvement, but maybe . . . As the manual states, this might take some experimentation with a lot of different tracks.
I also like the option for minimizing iTunes interaction; it stops iTunes from actually playing the track silently along with BitPerfect. This, according to the manual, should minimize HD and CPU activity even more.
The manual is very well written, and covers all of the new features well. I'm impressed with this new version so far. It looks like new purchasers of BitPerfect will have to lay out the grand sum of $10.00 for all of this (a huge bargain, I think) but updating from earlier versions is free.
The only other player I've used is Pure Music, and BitPerfect easily matches it in sound quality, and improves greatly on Pure Music's awkward interface by having only its dismissible preference panes.
I'm listening to Steely Dan's "The Last Mall" from "Everything Must Go" right now--the difference in sound when toggling BitPerfect on and off is very evident with this track.
My wish list now would be to add some kind of plug-in capability for version 1.??? . . .