which is more important, getting the data on/off the disk fast (because you are working on something and the audio is just background music) or the audio (because you are playing a live concert and the disk I/O is just background logging)
as another poster mentioned, the definition of 'acceptable' is very poor.
larger buffers can solve most skipping problems (at the cost of added latency)
for audio-only playback, latency of a half second to a second could be acceptable (as long as you can silence the playback immediatly)
for video/audio playback significant latency is also acceptable, as long as you can know how much it is so that the video and audio can be delayed the same amount.
for recording, latency also isn't important
for live manipulation of sound (record sound, modify it, and play it back) latency is critical.