Wanted to ask what the impact of switching to CoreAudio drivers are for SDJ from SSL?

So far I have seen/heard:

A different sound - I can deal with that, although it's annoying because SDJ now sounds like Traktor, and I LIKED the SSL sound.

Increased CPU load/USB dropouts - Not good, it's making my MBP obsolete.

I just saw that instead of using the "proprietary drivers" Serato advertised for Scratch Live which was a massive draw for me for that particular platform, SDJ now makes use of the Mac's standard CoreAudio drivers to pass signals. I thought the music sounded different on an SL4 when being run by different programs.

I performed a null test on a test song for both SDJ and SSL and did not receive a cancelled file. This leads me to conclude that SDJ and SSL handle audio differently (duh, serato frickin told us so).

Older macbooks (circa 2009) are unable to handle a 2ms connection between SDJ and our studio's NS7 without lowering latency to 20ms.

My 2010 MBP was constantly getting USB/dropout notifications at 2ms on SDJ and seeing over 70% CPU load while it performs flawlessly @ 1ms on SSL.

Now I understand that SDJ 1.6 is beta and has yet to be optimized, etc, however I am definitely taking a noteable performance hit that, in my own anecdotal experience, is similar to what SDJ did to an 2009 MacBook Pro way back when SDJ for NS7 was first released.

If possible I would also like to understand a bit better the rationale behind the switch from native drivers to CoreAudio?