For the Criterion ones I know there is. I only have four of them in my collection, but they are really good quality picture. I even saw Seven Samurai which they put out. A 1954 movie, but flawless transfer. No dust, almost no noticible scratches on the film stock.
As for whether it's worth buying those over regular versions, that's up to you. I'm a DVD junkie, I love the extras, which is why I have a few of the ones I do. Since you're not, the only reason I'd suggest doing it is if 1) you LOVE the movie and are willing to spend potentially quite a bit more for a superior transfer of it, 2) Criterion is the only company putting out the disc, or 3) your hardware is of the quality where you can see the differnce (ie, HDTV widescreen). Otherwise, stick to the regular stuff and spend what you save on more.
Can't comment on Superbit. All the movies the have that I'd want I'd already bought before or am not willing to get at those prices. Don't know anyone who has compared the SB and non-SB versions, so can't say.