I have read all the posts and I am somewhat confused about the advantagesof alkaline over acid, specifically in respect of staining developers. One post says no effect on staining with pyro while another says there is an effect. In the case of no effect it is clearly based on pyro and actual experience while I wasn't sure if the other poster was talking from experience of trying both alkaline and acid or was taking the use of alkaline as being better as perceived wisdom.
Closer to home i.e. the U.K. a popular staining developer is Prescysol which may or may not be similar to pyro in terms of the effect of acid fixer and the maker most certainly recommends an alkaline fixer. Has anyone done an experiment of trying a roll in Prescysol with acid then one with an alkaline fixer to see if there is an effect on stain. Clearly if there is an adverse effect on stain from acid fixer then not to use alkaline negates the benefit of using Prescysol in the first place and the case for an alkaline fixer is proven - at least in the case of Prescysol.