Hello shapiro, the only one of my tree peonies that has bloomed is the rockii. It is supposed to have a wonderful fragrance and everyone who came close enough to smell it was delighted. However, scent is a very individual experience.

I dislike the smell of osmanthus fragrans which is on almost everyone's list of top 5 most fragrant plants. Go figure!
My advice (for plants that are as pricey as tree peonies) is sniff before you buy. What are the names of the tree peonies that have smelled bad to you?

For me the vast majority of peonies have a somewhat unpleasant smell. They all smell to my nose like "fragrant rubber." I did make a discovery the other day, however, if they smell bad up close, sometimes about 3 inches further out you get only the nice smell. Apparently it's the stamens that stink up close.

However, their smell is nothing like the stink I got this year from a bunch of Fritillaria imperialis that bloomed (smell almost exactly like skunk!), but I love the flowers on those bulbs, so I don't worry about it.

--Ron