i prefer more LR over bio balls personally, but i do not think bio balls are a waste or bad. I have seen beautiful FO and FOWLR tanks use lots of bio balls, and i've seen many tanks around that do not use a "conventional" set-up like most of us here use.
The reasons i prefer live rock over bio balls are:
1) More natural, and nice to look at in the tank.
2)Easily supports coralline, which is very nice to have in a tank, as it eats away your ammonia and phosphates
3) It does the same thing as bio-balls, but i believe it does it more afflictively
4)Live rock never has to be rinsed, or have any anything done to it other than cure it (and i guess scrub if you have hair algae or something)
5) Provides many little homes, holes, and crevices, for not only the live stock you put into the tank to hide in, but also the beneficial microorganisms to hide in and reproduce in.
6) Live rock a lot of the time is kept right in the tank, and with bio balls, you do not have this option, you have to keep the bio balls in an external filter, where as live rock can be kept internally in the tank, or in an external filter as well.
but i too do believe that bio balls dont get the reputation they deserve.
The reasons i prefer live rock over bio balls are:
1) More natural, and nice to look at in the tank.
2)Easily supports coralline, which is very nice to have in a tank, as it eats away your ammonia and phosphates
3) It does the same thing as bio-balls, but i believe it does it more afflictively
4)Live rock never has to be rinsed, or have any anything done to it other than cure it (and i guess scrub if you have hair algae or something)
5) Provides many little homes, holes, and crevices, for not only the live stock you put into the tank to hide in, but also the beneficial microorganisms to hide in and reproduce in.
6) Live rock a lot of the time is kept right in the tank, and with bio balls, you do not have this option, you have to keep the bio balls in an external filter, where as live rock can be kept internally in the tank, or in an external filter as well.
but i too do believe that bio balls dont get the reputation they deserve.