Just to avoid confusion... since I was slightly confused when I first read it and had to refresh my memory: The "Extigy" and "MP3+" were external USB sound devices. I'm not sure why a blurb about them appears in an article about the SB Live Mac edition. (I'm actually disappointed there isn't some rudimentary support for SB Live in OS X, since I have a pile of them in the junk card box and I could use another analog input on my G4 tower.)
That Dell OEM card is pure, unadulterated evil. The ALSA driver for Linux didn't recognize it for a *long* time, and as I recall if you pulled it out of your Dell and replaced it with something that actually worked you'd lose the front panel audio jack.
Anyway, all Soundblaster Live cards suffered from PCI bus compatibility issues. It particularly affected VIA PCI bridges (actual hard crashes) but even with Intel boards you'd sometimes end up with weird voodoo. I have to wonder if hardware issues (in addition to low sales) are what *really* doomed the Mac version. When it comes to PCI compatibility I've always found Macs, particularly old ones, to be... "touchy".