I remember this plant from my previous tenure in China Valley. It didn't flower much, presumably the plants were too young. Horrible soil and full sun destroyed the appearance of the plants in summer; the leaves yellowed and browned with areas of dieback here and there. A number of years later, the soil is a bit better, there's some shade from maturing trees, and they Neillias are attractive.
They are working now for sure, no diseases, and they're Rosaceous, arching stems to ~5', suckers madly. Good cover for a large area. It would take, does take, serious maintenance to restrict the spread. Still....it's lovely.