You can have a love-hate relationship with 4 O'Clocks. They come back every year. The flowers smell divine. They can create a nice bush when planted together. They are healthy, full sun plants. However, they reseed VERY easily to the point some consider them invasive. Personally, I love them and find them easy enough to pull the ones that pop up where they are not wanted.
Wait and watch what they do for you for a season. You may come to love them as much as the previous homeowner.