Diann, that is such a beauty!
Alana, sounds like you'd be the one to ask this- is it standard practice for growers to graft tree peonies on herbaceous peony roots? I had a cheap tree peony from a box store that I had for several years, and one year a pink single herbaceous one grew from the root. I cut it off and it seemed fine.
I think I've stumbled upon a most gorgeous companion plant for Peonies- Painted Daisies. I have never actually seen one in person till now, had tried without luck to grow them in the past, but the plants I started from seed in '08 are finally blooming! And they're right next to 3 clumps of Peonies in pink and blush that have big buds about to start opening. The Painted Daisies are true pinks and magentas that match Peony hues perfectly, and I think the contrast in forms will be so pretty! Once they're all completely open I'll be sure to get pics.