Well, I'll tell you. I have used an acid stop bath, mixed at the recommended strength, on films for many years. A while back, I experimented with using a water wash as a stop bath just to see if there was any appreciable difference in the negatives. The comparison films were shot under similar, but not identical, conditions, leaving some wiggle room there to argue my results.

Bottom line is that I really couldn't see a whole lot of difference in the negatives, and even less when it came to the resulting prints. The differences could easily be chalked up to the fact that my exposures were not made under identical conditions, small development time deviations, and maybe even the phase of the moon. What I did find though is that my fixing bath (acid fixer) did not last nearly as long without having used the acid stop.

The only complaint I have with indicating stop baths is the yellow dye that gets carried over to the fixer. I eliminate the problem by washing the film with a couple of changes of water between the stop and fixer. Everything works out fine.

And what's the story about the smell? I hear a lot of complaints about that, but I've got to wonder what else is going on. Stop bath, if used at the recommended strength, really doesn't smell all that much. True, there is that vinegar odor, but it should not be so strong as to be irritating to most people. If the smell is really bothersome, then perhaps something else is wrong and needs to be corrected. Maybe the stop bath is mixed up too strongly, or more ventilation in the work area is needed. For those who are extraordinarily sensitive to acetic acid, a good substitute is citric acid with no odor.