FWIW, on page 2 of
this thread you can see how I tried to make a "flat top" bommie in my cube tank. If it weren't for the anemone I would have made it a more tapered mountain. I got lucky, I had visions of needing to make a PVC or eggcrate substructure to keep it open but I managed to make it fairly open yet stable just by stacking. There are lots of caves and you can even see through to the other side in places. My cucumber is constantly in and out of the caves. Anyhow I've always been partial to the bommie style aquascaping and I think a cube lends itself well to this style, although if done right the backwall style can work well too.
Snoop Dog did an awesome job of aquascaping in his cube, which you can see on page 6 of
this thread. His seems to be a hybrid of the bommie and backwall styles but what I really like is how he managed to make so many coral attachment shelves. If I was going for a SPS tank I'd want to make it something like that, that's awesome.
Anyhow HTH. cheers
