Bio balls/rock rubble will do basically the same thing, and give you the same issues down the road, unless they are maintained properly. Both will help in the denitrification process. Both will also become nitrate factories in the long run unless you maintain them.

To maintain the bioballs/rock rubble, you will have to periodically remove the media and rinse, then replace them. This will help with not getting elevated nitrates in your tank. When you just leave them in your setup with no maintanance is where the bioballs got their bad rep. It also seems that the beleife that rubble rock is better has taken hold, but in my experiance, unless the rocks are large enough to break down nitrates, they are the same and need to be maintained the same.

As long as you have enough live rock in your tank, neither is needed. Your live rock will serve the same purpose, without the maintanance.

There are many ways to go about setting up a tank, and this one is tried and true, but unless I am running a FO with no live rock I prefer other uses of space. On a tank you are describing I would recomend good live rock in the tank and carbon and po4 reducer in the chambers. If you can, use some space to get a skimmer on line also.

But- just as your boss says- bioballs dont desearve their bad rep as long as they are maintained. I swear by them too, but just dont see the need in a reef tank or in a tank that has established live rock.