I originally purchasec caulerpa for my fuge. It grew like wildfire (had a bit of a nutrient problem in the beginning), and I was going to keep it. Then I started reading all these things about it going sexual, and how that can crash the tank. The last thing I want is something that is supposed to help my tank be healthy actually kill my tank.
Turns out, my lfs owner had a bunch of extra cheato from his fuge, so he sold me a ball. I pulled mostly all of hte caulerpa out of the fuge and replaced it with chaeto. I have a feeling I will be pulling caulerpa for a while though.
Personally, I think the cheato looks nicer, much less 'weedy' than the caulerpa.