I actually give Auguste Renoir a 5 for fragrance as I only grow highly fragrant roses in humid Maryland. It is the most fragrant rose I have grown over the past 30 years (about 30 different hybrids). I averaged score at 4 as it is not a classic formed rose and the heads are so heavy they will frequently droop. From that view it would score a 3. Unlike many of the highly fragrant roses (Bellaroma, Pope John Paul, McCartney,etc ) you will start to sense the Auguste Renoir perfume from 10 ft away in hot summer sun. I have one left that is is 20 years old and suffered through botrytis - spotted it late. Overall it is disease resistant and with own-roots it has come back. I recently had to take a drastic action and transplant it as new trees were shading it. Even with the harsh transplant it came back and bloomed well. I suspect from my own experience that what I thought was browning of the petals was actually onset of botrytis. That may not be true for those with desert conditions as I doubt botrytis is found there.
I need to learn how to take cuttings of it and start new roses.