Swiss "Colour Science" negative film IT8 targets for scanner profiles

I discovered recently this information:

http://www.colour-science.com/qualit...roductlist.htm

Since Wolf Faust does not offer any negative targets for scanner
profiles, I was intrigued by this idea of IT8 film strip with
additional +/- steps exposure on them. Negative film has a lot
of latitude and such exposures might be of great interest.

I wonder if someone has been using these targets? Are they good
and exact?

Furthermore, they also have Agfa slide targets on their list,
which Wolf Faust still does not offer! I am tempted to order!

Thomas