I bought one of these in autumn last year, in an overpriced and rather run-down state, just because I'm a sucker for good scent and thought the poor thing needed a good home.
After being planted last autumn in the local volcanic clay-based soil, heavily amended with premium garden soil from the local landscape supplier, and with a few other goodies added, this rose finally seems to be settling in well after coming out of a very long dormancy.
When purchased it had tiny leaves, only around a centimetre (or half inch) long, and did very little all through winter and spring. Halfway through the sub-tropical summer now and decent foliage is becoming abundant, with leaves up to 50 mm (two inches) or so long.
I have seen black spot on it, but it doesn't seem to be particularly susceptible. I have sprayed it once or twice when it was looking a bit crook earlier on, but intend to avoid spraying as much as possible. Foliage is currently clean.
So far it hasn't flowered this year, which is ok by me since I'm just glad to see it getting more robust. It did put out a couple of flowers last autumn before going into winter dormancy. The scent was everything it was supposed to be, but the flowers had very weak stems and nodded badly. I put this down to the poor health of the plant at the time, since nodding is not a common HT trait.
I'll keep on eye on it and see how it goes in this climate, as I've read varying reports about survival of Delbards in general.
Update: It doesn't look like I'll get an autumn flush this year. So far there is no sign of buds. However, the plant seems healthy. Foliage is abundant and there is only a little black spot on some of the lower leaves, despite plenty of heat and humidity recently and despite not being sprayed for ages.
lt gives the impression of being generally content, but not in any particular hurry. That's ok with me, since it was a rescue mission when I bought it and I don't mind if it takes a year off.
Another update, late August 2015: Winter this year was very mild, so it's getting an early start on spring. Making a nice array of buds at the moment and seems happy. Still a small and rather sparse bush, but appears to be strong. This is despite me having to transplant it again last summer, which it wasn't particularly thrilled about.
Given the rough start it's had in life I'd say this is a generally robust rose, even if I don't have the best example of it. I may try another one sometime, from a better source, as the scent really is superb.
Haven't sprayed the thing for months, but am going to now since the heat and black spot is coming on and I want to give it a good chance to get established. Ultimately it will have to survive with little or no spraying, and I think it will be able to do this. Heat doesn't seem to worry it. As far as I can tell at the moment, resistance to disease in this climate seems pretty good.