I've original Yamaha WF192XG and original sblive value.
If comparing the midi sound,
Yamaha (just 1M rom storing 2M samples) beats sblive (using standard 8M soundfont set), especially classical music midi.
however, if you use a 32M or even larger GM/GS soundfont set, sblive can counter attack.
the great point of sblive is unlimit/2 soundfont size if you've unlimit system memory.
the yamaha eats more cpu power than sblive, when it's loading in IE while playing mp3,
the mp3 playback is interrupted with a very short pause.
yamaha wf192xg came out before sblive, wf192xg's main targets were awe64 and other isa cards. It's almost the first pci sound card.
sblive is way better than wf192xg in most areas.
now the new CS4630 is better than sblive,
so CS4630 is sure much way better than YMF744.
If you want cheap sound card, check out the CS4624 (Hercules Fortissimo II), just less DLS and 5.1 output.