Then the only solution is to test for yourself. When I present data (characteristic curves) for films like CMS20, people argue I'm wrong, but despite repeated requests nobody has presented any curves to support what they think they see out of these films. Instead they post image scans that contradict their own claims. More examples just above - high contrast, harsh gradation, blank shadows etc. If that is the look you are after I have no argument against it. After all photography is about personal aesthetics.
Originally Posted by fatso
If you are at all concerned with tonality and flexibility under a variety of contrast conditions please do your own testing and be very skeptical of what you read. If you like what you're seeing, by all means use these films. Just be aware they are special purpose films and as such will never give you anywhere near the overall utility, flexibility and quality of general purpose films. There are always tradeoffs.