As a DAW user this is what always concerns me with upgrades/dates
so I was reading/watching all I could just before 10.9 shipped.
In the upcoming OSX.10.10. I have yet to read/see any info regarding changes to Core audio/MIDI.
Of course things may always change but so far so good.
What I HAVE noticed over these years tho’ is usually every new OS
(and most new apps/plugs) wants a lil more ‘cpu juice’ to do new things.
BTW
We have yet to deal with 10.9.4 and any surprises it may bring.
Good Luck!
{‘-’}