The reason for the desired upgrade....
I have been running this one with very minimal equipment. No skimmer. Just a canister filter, two Koralia pumps and a heater. I have only a few fish - Clown (was a gift), firefish, blue damsel and a six line wrasse....because people would look at me funny if I had a fish tank with no fish. I really have always been in love with the corals.
So lately I have been looking to really up the coral collection and wanted the ability to also keep SPS....but I am thinking that this tank would not be worth upgrading (skimmer, sump, calcium reactor) and if I am going to do this bigger I might as well do it right the first time.