We had a mimosa tree until earlier this year. Unlike many of those seen in this area (just north of Atlanta) that are scraggly or bushy messes, this fifteen year old specimen had a beautiful shape, its 6' tall trunk ending like an upturned hand in branches that extended about 15'. The blooms on this tree were a light pink with a strong fragrance. I loved it!
With that said, mimosas are very messy when shedding spent flowers and seedpods. Our tree was constantly losing branches due to the brittleness of the wood. And Dear God, did it make babies all over the place!!!!! And unlike many prolific seeders, mimosas have a tap root. If you don't get the babies when they are small, they can be very difficult to remove, even with a smaller seedling (say 1-3').
This year, the mimosa was late in leafing out and when we started into our normal very dry summer, it gave up the ghost. It exuded a very foul smelling liquid as it died.
All in all, I will probably plant another mimosa but it will be in the back yard or pasture so it doesn't cause as many problems :)