i just saw this in my wildlive nurseries catalog, jsut rec'd today! i can't help on aggressiveness, but no one else has posted. i will write what the catalog says:

"Calamagrostis canadensis. Bluejoint grass is a tall growing (2-5'), slender, cool season grass. It prefers areas where the soil is moist or soggy all or part of the year, and area flooded seasonally. It is dominant in low prairies and fresh (wet) meadows. Likes full sun, stands up well throughout the winter months, providing food and cover for wildlife. Plant Spring through Fall..."