@rsn
Real DOS? Now, that's ages ago when I tested this
But yes, I think I had some DOS drivers for this card too.
[edit]
BINGO!
About the buffer ... that is clearly dependent on both OS and CPU. With my old CPU (AthlonXP T-bird ~1 GHz), it worked better with "4" (Win98SE) resp. "3" (Windows 2000). Now, on Windows 2000, "2" works great, but takes some resources; i. e. nor is it possible to run too many apps at the same time when WinUAE is running; so if you do want to have lots of them running, live with some (minimum) sound delay issues, and go a bit higher with the buffer.
Note, sound is based on DirectSound (at least I reckon that it still is). DirectX too has improved a flipping lot in the last years, so comparisons are fairly hard to make.