New Dawn has been a success story for me.
Planted in a corner where she doesn't get much sun (well, nothing in my garden gets much sun!), she had to climb up the garage which she achieved in her first year. Once up, she now spreads vertically on top of the wall and the garage roof.
There is a huge hazel tree growing in the park next to the garage, and in the autumn the garage roof gets sprayed with both hazel nut clusters and leaves. When I don't sweep them off meticulously, they decompose quickly into some sort of topsoil, allowing both grass to grow and - more importantly - New Dawn's branches to form roots.
In spring, when pruning, I climb onto the garage, pull at New Dawn's branches, see where the roots have formed, cut the branch off and plant it into a pot. The loose nature of the "topsoil" makes removing the rooted branches super easy.
This way, I have been multiplying my New Dawn without any effort on my part, and clones of her are now growing relatively happily as part of a (future) rose hedge in my Eifel orchard - I say relatively happy because they are constantly threatened by voles, deer and harsh conditions. But they do establish themselves where lots of other roses fail.
If you want a robust and beautiful rose, have the space but not the time (with New Dawn, I only prune what's in the way and never dead-head) AND don't mind the vicious thorniness then New Dawn is for you.
PS: Veilchenblau which spreads on the same garage roof never forms roots.