I have both versions. The original and superbit do not differ drastically in picture. Although the superbit does look a little better, its not like it breaks the bounds of DVD encoding. You'd think from the marketing fluff on Superbits that they look HD. Its still a DVD and hence fixed in resolution, its just the encoding was done at a higher bitrate and hence fewer compression artifacts.
The sound however is worlds apart. The original does not hold a candle to the superbit version's DTS, both in general quality and in surround mixing.
I sprung for the Superbit at Best Buy when it was $9.99. Worth every penny, even though I already owned the original.
~Josh