I had the same experience in very humid Arkansas. It isn't immune to blackspot, but the astounding vigor of the plant means that any infection is hardly noticeable.
I do not know why it is listed as 7B/ and above because it seems not to be any more delicate or need more protection than my other hybrid teas. It is really good in scent and form and a little different than most hybrid teas in these areas.
It grows in zone 6 in The Rosarium of Winschoten. And it does well. Even survived the bad winter of 2012, when the temps were relatively high until January 25 and then plummeted for weeks with bare frosts and bright sunlight. (at several nights even down to -20°C!
I cannot pass this rose by without sticking my nose in a bloom. The blooms don't last and it doesn't bloom a lot for me (it's in a pot) but, the color is wonderful and the fragrance is amazing. I would not be without this rose.
