I disagree. Both of his postings were entirely negative, along the lines of "Well you are completely wrong but I cannot give any evidence, anyway I know this and you dont".
That statement is completely untrue. Show what comments I've made in this thread that could possibly be interpreted in that way.
All my comments in this thread and all threads on this forum, for that matter, are based on either personal experience or personal opinion based on rational deduction from the evidence available as well as the opinion of others. I back up my opinions with photographic examples when possible.
If you would like to back up your opinion with a before/after example of how a scanner calibrated with an IT8 target can help a faded slide, then please do so, but make sure it really is a faded slide.
I have literally thousands of faded slides & negatives. Do you think I wouldn't be calibrating my scanner if I thought it would make a difference? Do you think I'm mad? The fact is, I have few slides that are not faded to some degree. My most recently shot film before I switched to digital about 6 years ago was Fuji Reala and Kodak Royal Gold color negative film.
I have no trouble getting the hues very close when scanning negative film because the scanner software includes a variety of profiles for different negative film types, which make a huge difference to the color and tonality. However, Vuescan also contains a few slide profiles, namely, Generic, Kodak Kodachrome, and Kodak Ectachrome.
With the slides I'm scanning, it makes not a whit of difference which profile I choose. The preview looks the same. As I mentioned before, the examples I've seen on the net lead me to believe that profiling with an IT8 target makes only a subtle difference. If your slide is faded by more than a subtle degree, I can't see the point.
I'm relying upon people like you, so convinced it does make a difference, to show me some comparisons. If we were to switch places and I was the one arguing the point that a calibration makes a worthwhile difference to the preview of a faded slide, I'd show you. I wouldn't expect you to take my word for it.