Years, ago, I used a very diluted mix of glacial acid acid for stop during film development; my dilution was much less than generally recommended at the time. Due to occasional issues with pinholes, etc, and the use of pyro-type film developers I seemed to naturally migrate away from acid stops to using water only. If you use alkaline-based fixers (e.g. Photo Formulary's TF-4), then acid stop baths really shouldn't be used. My vote is: use water.

Hope this helps.