Neal stated: "Could be my climate, but several of the modern hybrid teas, grandifloras, and floribundas I've tried on their own roots have remained very small. However the more recently introduced Kordes varieties I've tried are performing well. I read somewhere that they trial them on their own roots."
Apparently, in 2000, Kordes did test their all their roses as own roots. This was confirmed by 2 reliable sources. In 2000 Kordes started testing all their roses as own roots in there own fields and each one was evaluated to see if it could survive and was healthy without grafting. It is my understanding, that the ones they offered from 2002 to date are good as own roots.
I would assume there have to be some Kordes before 2000 that are good as own roots. It seems to me, that's why they were testing them all to find out which ones they wanted to keep in their hybridizing program.
