I haven't used the S&V disc, but the Avia disc is perfectly fine. It's a little pricey, though. If you go out and rent "From Hell" or any of a handful of other discs that have calibration options as part of the extras, that will work pretty well if you're not ready to shell out the dough for one of the dedicated discs. That got me 90% of the way until I bought the Avia disc.
The Avia disc (and presumably the S&V disc) offer a wider range of test tones and scenarios, as well as some nifty colored filters to help you set up your TV's color accurately.
