I used to have caulerpa prolifera, and have actually gone back to get more. It does a great job at nutrient exportation and looks nice. All caulerpa will go sexual if it gets overcrowded and can't spread out.
My advice:
If on the display tank, keep it on the sand bed and regularly trim it when it gets close to touching rocks; once it makes contact with rocks, there's no getting it out (truthfully there are some and I can share them, but for arguments sake, and ease of headache, I'm saying none). As far as tank mates, I know my long spine urchin and fox face can go through a ton a day, with my fox face preferring it over regular algae (emphasis on mine) so watch to see if any of your inhabitants will eat it faster than it will grow.
If in the sump, just dump it and make sure it has rocks or sand to attach to. Also print regularly to keep it from over crowding.