not sure about equipment.
I think the BIG plus is the opening in options when it comes to livestock.
I've DREAMED of having an
Achilles tang...which really is NOT an option until you get into the larger systems. So that's what I'm gonna do. Build my in-wall 330, and make that dream come true.
but not just an opening of options, but a difference in quantity too.
I started out in this hobby, and knew you couldn't keep many fish in a 20 or 30 gal system. So I gave in, and bought a 75...biggest tank I'd ever owned up until then. Thinking I could load it up.
While waiting for it to cycle, I found TRT, and was sad to find out...that my newly aquired mega-tank (in my eyes), was really mid-sized at best. And that I'd probably only be able to keep a few fish.
That was a bit heartbreaking to me. But when you get into the larger tanks...suddenly you can get a school of Chromis, or MORE than one tang (if done right). It's a whole new world.
But as far as equipment...only thing(s) I can really think of are Tunze's Streams and wave-makes (good ones). When the tanks bigger, you suddenly have the option of adding this type of equipment.
But other stuff...I think you can do on a smaller tank too. Lights, skimmer, Ca reactor, etc...