This must depend on just how good your system is at 'streaming'.

I have seen the jerky scrollbar, but only if I have a lot of tracks and a lot of effects eating resources. I'm talking 25-35 audio tracks and maybe 20-30 FX (or more) running. I should do an actual count of FX some time when it happens. Since they are hidden for each track and you can only view one track's FX at a time, I really have no idea how many are running, but I am certain it is at least this high when I have this many tracks...

I still believe it is by design that the video suffers before the audio.

I would rather have the screen stall than lose a take.

I do not work here, but the benefits are still awesome
Make your sound your own!