I'll take Extendos anyday. Extendos is way easier to set up and it works on my system flawlessly. I simply can't figure out those configuration files. I HATE DOS...fiddling with line commands, config files, etc.
Extendos DOES make PRG files out of WAV files and you can play them from the desktop by double-clicking on it just like Spin.
Extendos is worth every penny I spent on it and worth the time saved from setting up the horrendous DOS-like config Spin files.
I'll stop now before a CD-ROM drivers war starts here. ;-)