Well I'll offer my opinion then
I had some halimeda in my tank last year. Personally, I love the stuff, I really like the look of it and as a dual purpose it uses up nutrients that other nasty (ie. caulerpa) macroalgaes might otherwise use. You may not want it in a tank where you are dosing calcium but I had a reactor so I didn't see it being a problem. I was doing pretty well growing it last year until the dinoflagellates wiped it out.
HTH
Christy
