Charles Austin is a delightful rose in this zone. My plant is on it's own roots and has Wintered very well.  I've not experienced many fungal problems here. There was a small amount of black spot this year, but the Spring was very wet.  Charles Austin blooms in flushes, and I wish rebloom was a bit quicker. When it is in bloom all is forgiven. I've had no nodding or weak stem problems with this variety.