It is a great idea but for whom does it answer what question? When I started my journey into this odd realm of trying this and that, I was exploring methods to achieve a certain look in my work. Even now, I am trying to improve that certain look as I go on. I have explored about 8 different B&W film developers trying to get the right accutance for a sharp look for a particular degree of enlargment. So what works great for one format is too grainy for small format or too soft for a larger format. With these 8 different developers, I have tried about 8 different emulsions as well, that all respond a little differently in each of the 8 different developers I have tried. That is 64 combinations of emulsions and developers to try to meet a certain criteria. Then there are other considerations, once a combination has been found, it may have drawbacks. I like TRI-X in microdol - I don't like the loss of one stop film speed, I don't like the capacity and shelf life. The price is OK. Now I am working with PC-TEA to see if the results are as good without these objections. MYTOL was an improvement over microdol in that I got the film speed back but still the other considerations had not changed. For larger formats, PMK was great but not very enlargable. DiXactol gave the same accutance with finer grain at higher cost. Now I use Pyrocat HD and get the same performance as DiXactol cheaper and easier. So this is what I use for sheet film - from 4x5 that gets enlarged to 8x10 that is only contact printed. - I get the accutance I want and the grain is fine with the added benefit of highlight compensation. For formats that get enlarged much more, I am looking at PC-TEA - I have not settled on it but the road looks promising. I can always come back to MYTOL if it doesn't work out.
Now having said all this, would a chart have shortened my path? Would I have started out with where I am now? Probably not, because until I made an 8x10 that looked like a collection of dots because of the huge grain, I would not have appreciated a combination that keeps the grain small. If I had not made a print that looks mushy, I would not have wanted to see the sharpness that can be had with a high accutance developer. It is the learning through experimenting that set the definition for the spec. It is the same thing for lenses and formats as well. And I have not even mentioned the third dimention which is paper and paper developer. With staining film developer, there is a different response to VC verses Graded papers. I tend to like to use Graded fiber papers where the stain is less useful but still provides some grain masking. And then there is AZO. Yes - I do keep Amidol on hand and I save up all my contact work and batch it out a few times a year.
So the question is as big as the choice of what to shoot, how to depict it and what size media will it finally be presented on. I think a chart that listed - Cost per roll/sheet - staining/tanning or non/staining tanning - high accutance - fine grain- high solivent - surface developer - toxisity - shelf life - would be very handy. - But I think that question is as easily answered as an idividual who pops up here and states what they want to achieve and then does what we all do - try and see. -
So that is my $.10 worth ....