Wider and better hardware support. Which system offers the best hardware support and feature set? As far as I know, ALSA is the only one of both which actually supports "advanced" features in hardware such as Sound Blaster Audigy and Live! cards, like EAX (it has an EAX compiler and editor EMU10K1 based cards)... This doesn't mean that the driver or the library supports decoding of EAX in real time, only setting some effects for playback (like the EAX panel in Windows for the Live! and Audigy cards). I'm aware that the degree of support in most cases will depend on how much documentation the developers of each system had access to, in which case I see OSS with an advantage, as being a commercial product, they most likely had access to a wider variety of hardware than ALSA developers (I could be wrong, though) and support features like hardware mixing in hardware that actually has it, while ALSA does not support it. Again, I am no expert on both systems, so I can't say whic it is.