After a delay of several months, I did the test I had promised to do: Shot a Delta 100 and a Fuji Acros (120) under identical conditions (two hasselblad magazines, same camera+lens same subject same time) and developed them in the same tank (on one reel). The results are not the same. But they are very close to each other. By viewing the negs on the light table, I found some difference in the highlights (the Acros looks more contrasty) and a small difference in base tonality, so small that could be my imagination. I wouldn't say the two films are identical, but I can say they are pretty close. In the following week I will do some prints and see how they compare in grain, acutance etc. If someone wants to test the negs with some special equipment (densitometer, microscope, something else) I can send them to him/her. On the other hand, you can all try it to see for yourselves.